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FIELD OF THE INVENTION
The present invention relates to the field of music analysis and teaching,
and more specifically, to a method and apparatus for comparative analysis
of an original musical recording with a synthetically generated version of
the same recording. In particular, the apparatus of the present invention
enables a user to play and compare a musical recording, having a number of
instrumental parts, with a synthetically generated version of the same
recording in which the individual instrumental parts have been recorded
separately and are therefore individually accessible.
BACKGROUND OF THE INVENTION
Sound recordings, and in particular, musical performances having a number
of instrumental parts, are widely available on a large number of mediums.
These mediums include traditional phonograph records and magnetic tapes,
as well as optical compact discs and magnetic disks. The sound recording
is stored on these mediums as a composite audio signal which represents
the sum total of all individual component parts of the recording. In the
case of a musical performance, the component instrumental parts are
generally performed in synchronization and the composite musical
performance recorded as a single audio signal that is stored in either an
analog or digital format.
Recorded musical performances are used extensively in the teaching and
analysis of musical composition, performance and conducting. Many music
students desiring to learn an instrumental part in a musical performance
still rely on the conventional technique of visually following a copy of
the musical score in real time with a recorded performance of the same
musical score. Other students attempt to "play along" with the recorded
performance of the score at the passage(s) which they desire to learn.
Unfortunately, few students can read an orchestral or big band score in
real time while listening to a recorded performance. Even fewer students
can perform an instrumental part from an orchestral or big band score in
real time while listening to a recorded performance. "Practice" records,
in which one instrumental part from the musical performance has been
eliminated, are available to allow the music student to play along with
the recording and perform the missing instrumental part. Unfortunately
such records are available for only a limited number of musical
performances and with even fewer instrumental combinations.
The above techniques can be frustrating, particularly if a musical passage
is difficult, since few playback devices provide facilities for chancing
the tempo of the recorded performance, and then only with a corresponding
change in pitch. Further, the listener is unable to selectively listen to
individual parts of the musical performance without hearing all
instrumental parts simultaneously. Finally, the listener is bound to the
instrumentation and orchestration of the musical performance as recorded
and, at best, can only imagine how the score would sound as played by
different musical instruments.
It should be noted, that during the conventional recording of an analog
audio signal representing a musical performance, the individual
instrumental parts can be each recorded on separate tracks of a magnetic
tape and can be individually listened to or muted to facilitate audio
mixing and recording of the composite audio signal. However, this
technique requires a multitrack master tape, each track containing an
individual recording of an instrumental part, a multitrack tape deck and a
multitrack mixing console. The above equipment is typically available only
in well equipped audio recording studios which are usually inaccessible to
most music students. Multitrack master tapes are expensive to reproduce,
are seldom, if ever, reproduced and are thus not available for student use
even if the equipment were available. Consequently, such a technique is
impractical and far too expensive for wide spread use as a method of
teaching or analyzing music composition and performance. Moreover,
classical music is seldom recorded via multitrack method. Thus, few
compositions normally used in music education would be available for study
by this method, even if well equipped studios were accessible.
Accordingly it is an object of present invention to provide a method and
apparatus for synthetically generating, storing and synchronizing a
collection of individual instrumental parts along with a composite pre
existing recording of a musical performance of the same instrumental
parts.
Another object of the present invention is to provide a method and
apparatus which enables a user to listen to a recorded musical
performance, stored as a composite audio signal comprised of all
instrumental parts, in conjunction with a performance of one or all parts
of the same musical score stored as a collection of individually recorded
instrumental parts.
A further object of the present invention is to provide a means by which a
user can dissect a synthesized performance to analyze individual
instrumental parts, repeating sections of the synthesized performance at
will and adding other instrumental parts until he understands how the
score is built, and possibly how it would sound if re-orchestrated for
different instruments.
Another object of the present invention is to provide a method of studying
music in which the student may utilize a synthesized version of a recorded
performance to assist him in studying an instrumental part wherein the
student can select various sections of the instrumental part for listening
and playing at a tempo with which the student feels comfortable.
A further object of the present invention is to provide an apparatus which
enables the user to listen to a synthesized version of a musical
performance in synchronization with an original recording of the same
performance or at a tempo which is different from that of the original
recorded performance.
Another object of the present invention is to provide a means by which the
user may select a segment of a synthesized performance and repeat it at
will with various permutations and combinations of such instrumental
parts.
A further object of the present invention is to provide a means by which
the user may selectively mute individual instrumental parts of the
synthesized performance with or without synchronization of the synthesized
performance to the originally recorded performance.
Yet another object of the present invention is to provide an apparatus
which enables a user to modify, store or augment a synthesized performance
and replay such a modified version of the synthesized performance in
synchronization with the originally recorded performance.
Still a further object of the present invention is to provide a storage
medium containing a composite audio signal, representing a musical
performance, timing and synchronization information, and a synthesized
musical performance, comprised of synthetically generated, individually
stored instrumental parts.
SUMMARY OF THE INVENTION
The foregoing and other objects of the present invention are achieved, with
a music analysis system which enables the user to listen to a synthesized
version of a musical performance in synchronization with an original
recording of the same musical performance. The system further provides
facilities for modifying, storing and replaying of the synthesized
performance with or without synchronization to the originally recorded
performance.
According to one embodiment of the present invention, a first storage
medium is provided for storing, preferably in digital format, an audio
signal representing a musical performance having a plurality of
instrumental parts. The storage medium further contains a timing code,
encoded to the audio signal for synchronization purposes, and beat markers
used to specify the rhythmic beats in the musical performance represented
by the audio signal. In addition to the recorded performance and
synchronization codes, the storage medium contains a synthesized version
of the same musical performance wherein the parameters of each
instrumental part are represented digitally and stored separately.
A second storage medium containing a variety of instrumental sounds which
have been digitally sampled thereon is used in conjunction with the
synthesized instrumental parts of the first storage medium to recreate the
complete synthesized performance.
The music analysis system of the present invention is a digital processor
based system including a digital processor, various types of memory, a
proprietary operating system and software, sound generation circuitry, a
control console for accepting and displayinq user information, and a
variety of input/output interfaces for communicating with peripherals
including those for the first and second storage mediums.
The method of studying and analyzing music facilitated by the music
analysis system enables a student to comparatively listen to an originally
recorded musical performance and then manipulate an identical synthesized
performance of the same musical composition (or score) to gain a better
understanding of the compositional, arranging and conducting or performing
techniques contained therein. The method of studying and analyzing a
musical performance may include any one or more of the following steps:
playing the synthesized performance with or without synchronization to the
original performance; listening to only a selected segment of either the
synthesized or original performance; listening to the synthesized
performance with one or more instrumental parts muted; changing the tempo
of the synthesized performance; reassigning various instrumental sounds to
the original instrumental part of the synthesized performance; and storing
any modifications to the synthesized performance for subsequent replay,
with or without synchronization to the original performance.
Accordingly, the music analysis system of the present invention, provides a
music student or teacher with a means which enables an understanding of an
original musical performance through analysis, modification, and
augmentation of a synthesized version of the same performance.
The invention will be more fully understood from the detailed description
set forth below, which should be read in conjunction with the accompanying
drawings. The invention is defined in the claims appended at the end of
the detailed description, which is offered by way of example only.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawing:
FIG. 1 diagram of the music analysis system of the present invention
including peripheral devices used in conjunction with the system;
FIG. 2 is a conceptual representation of the proprietary storage medium of
the present invention;
FIG. 3 is a flow chart illustrating the method steps used to create the
storage medium of FIG. 2;
FIG. 4 an illustration of a control panel for the system of FIG. 1;
FIG. 5 is an excerpt of an illustrative orchestral score; and
FIGS. 6A-E are flow charts indicating a possible sequences of instructional
commands for the system of FIG. 1 to facilitate the method of studying and
analyzing music of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides a music analysis system which enables the
user to listen to a synthesized version of a musical performance in
synchronization with an original recording of the same musical
performance. The system provides means for modification, storing and
replaying of the synthesized performance by the user.
Referring to FIG. 5, a segment of a musical score 40 is shown. Musical
score 40 is comprised of a plurality of musical staves 42-48. Each stave
contains the traditional musical notation for an individual instrumental
part. For example, stave 42 contains an instrumental part which is scored
for a violin. Stave 46 contains a instrumental part which is scored for a
viola. Each instrument part is comprised of a sequence of notations for
musical notes having distinct pitches and time values. Each instrumental
part is divided rhythmically into a number of finite time sections known
as bars. The bars 59A-59F of score 40 are notated by vertical lines on
staves 42-48 at locations 45A-E. Each musical bar contains a number of
musical beats (in this case 3), the number being dictated by the numerator
of the time signature at the beginning of the stave. When instrumental
parts are performed as notated on staves 42-48 respectively, a musical
performance results.
PROPRIETARY STORAGE MEDIUM
Referring to FIG. 2, a storage medium 12, preferably a compact optical
disc/ROM (CD ROM), is represented conceptually. For simplification, disc
12 has been divided into a number of tracks 12A-E. Track 12A is
symbolically illustrated as containing an analog representation of an
audio signal which has been stored on disc 12. Typically, audio track 12A
is an analog audio signal recording which has been digitally sampled and
stored. Preferably, the recording on audio track 12A represents a musical
performance which has multiple instrumental parts and is characterized by
a rhythmic sequence of musical beats, score 40 of FIG. 5 being an
illustrative score for such a performance.
Track 12B is a conceptual representation of a timing code used to
synchronize audio track 12A with other musical data. Preferably, a timing
code such as that used by the Society of Motion Picture and Television
Engineers (SMPTE), comprises time code track 12B. The SMPTE time code is
well understood by those skilled in the recording arts and will not be
described in detail here. Basically, a SMPTE time code is a series of
addresses that correspond to each 1/30 of a second time interval of a
track, from the beginning to the end of the track. A SMPTE time code
address has an eight digit format in the form of HH:MM:SS:FF, signifying
hours, minutes, seconds and frames where each second contains 30 frame.
For example, the first sonic event at the onset of audio track 12A will
have the SMPTE code address of 00:00:00:00, signifying zero hours, zero
minutes, zero seconds, and zero frames.
To facilitate synchronization of other musical data to audio track 12A, a
beat track 12C is added to precisely mark the occurrence of each rhythmic
beat of audio track 12A in relationship to time code track 12B.
Preferably, beat track 12C is a list or subset of the SMPTE time code
addresses of track 12B with each address corresponding to a beat in the
musical performance of audio track 12A. Beat track 12C further includes
bar and beat markers in the form of sequential reference numbers
corresponding to the sequence of SMPTE time code addresses contained
therein.
Audio track 12A, preferably containing a musical performance, time code
track 12B, preferably a SMPTE code, and beat track 12C, collectively
represent the original musical performance.
Track or tracks 12D, which may contain one or more tracks, represents a
synthesized version of the original musical performance. Track(s) 12D
contains, in a standardized digital format, the data necessary to
reconstruct each of the individual instrumental parts shown in score 40 of
FIG. 5. The digital format used to store the instrumental parts is
preferably the Musical Instrument Digital Interface protocol which is an
industry standard protocol, comprised of hardware and software, which
enables interfacing of devices made by different vendors.
The Musical Instrument Digital Interface (MIDI) protocol defines a number
of standardized digital formats for representing sonic parameters such as
pitch (frequency), volume (amplitude), timbre (harmonic content), rhythm
(duration), and envelope (volume/time relationship) of a sound or musical
note. The MIDI protocol further defines standards for storing and
representing polyphonic (more than one) sequences of sounds in the form of
conventional noted musical scores such as that shown in FIG. 5.
Basically, the MIDI protocol comprises a combination of dedicated circuitry
and accompanying software, which allows a sound which has been generated
or recorded by one MIDI device to be accessed by or played on another MIDI
device utilizing the same MIDI protocol. The MIDI protocol enables a user
to enter, in real time at a MIDI keyboard, all pitch and rhythmic
information necessary to generate a MIDI score of an instrumental part.
Supplemental parameters of the score such as tempo changes, performance
dynamics, and harmonic content of the individual instrumental part are
entered later. In this manner, the MIDI protocol enables storing of data
representing a complete musical score, including all data necessary to
regenerate the musical performance on another device, except for the
instrumental sounds which ar stored separately and are assignable by the
user.
The MIDI protocol is widely known and well within the scope of knowledge of
on reasonably skilled in the musical recording arts. Accordingly, a more
detailed description of the MIDI protocol is beyond the scope of this
document.
Track(s) 12D, shown conceptually in FIG. 2, contains individual MIDI
channels for the instrumental parts cf staves 42-48 of score 40,
respectively. Typically, each channel would be stored on a separate track.
Each MIDI channel contains all of the musical data necessary to recreate
one instrumental part, except for the actual instrumental sound data. Upon
playback, MIDI channels trigger instrumental sounds which have been
sampled digitally and stored in a separate ROM memory. Consequently,
track(s) 12D contains the MIDI channels which comprise the synthesized
version of the original musical performance stored in audio track 12A.
Track or tracks 12E contain information to be displayed to the user on
music analysis system 80 (FIG. 1). Such information typically includes the
disc number, title and composer's name, names and numbers of any movements
in the musical performance, the total time of the performance, the number
of rhythmic bars in each movement of the musical performance, a listing of
the instrumental parts designated in the score and the number of the MIDI
channels on which the corresponding instrumental parts of the synthesized
performance are stored.
Accordingly, disc 12 contains audio track 12A, preferably containing a
musical performance such as that represented in score 40, time code track
12B, preferably a SMPTE code, and beat track 12C, comprising a listing of
SMPTE addresses of track 12B at which rhythmic beats occur in audio track
12A. Tracks 12A-C collectively represent the audio and timing data of the
original musical performance. Additionally, track(s) 12D contain a
complete MIDI representation of the musical performance contained in track
12A whereby one MIDI channel has been allocated for each instrumental part
of the musical score. Track 12E contains user information for accessing
and identifying the data in tracks 12A-D. Thus, disc 12 contains an
original musical performance, a synthesized MIDI version of the same
musical performance, and timing and synchronization data necessary for
playing the synthesized MIDI performance in synchronization with the
original musical performance.
METHOD OF CREATING AND STORING PROPRIETARY INFORMATION
FIG. 3 illustrates the method steps used to generate the information stored
on disk 12. Typically, the information on tracks 12A-E is entered one
track at a time on a series of working magnetic tapes, the final version
of which is recorded onto disk 12 as described hereinafter. As indicated
by step 20 of FIG. 3, the first step of fabricating disk 12 is to record
an audio signal, preferably in digital format, on a magnetic tape.
Preferably, the recorded audio signal is representative of a musical
performance having a plurality of instrumental parts. The audio signal may
have originally been a digital recording or a previously recorded analog
signal which has been digitally sampled.
Next, as indicated by step 22, a timing code, preferably a SMPTE code, is
encoded with audio track 12A. Typically, audio track 12A will be re
recorded onto a second magnetic tape while a commercially available SMPTE
time code generator, synched to the tape recording device, generates SMPTE
time code data. A SMPTE time code generator suitably for use in the
present invention is commercially available under the tradename BTX Cypher
from Cipher Digital Inc , P.O. Box 170, Frederick, Ma. 21701. The
resulting working tape then contains audio track 12A and time code track
12B, comprised of sequential SMPTE addresses corresponding to every 1/30
of a second interval of audio track 12A.
Next, as indicated by step 24, beat track 12C is generated from audio track
12A and time code track 12B. Typically, beat track 12C is created using a
commercially available software package and a personal computer which
monitors time code track 12B in real time and, at a manually specified
instant, numbers and records the corresponding SMPTE time code address of
track 12B. A software package suitable for use in the present invention is
commercially available under the tradename Professional Performer Version
2.41 from Mark of the Unicorn, Inc., Cambridge, Mass. 02142. Preferably, a
user will listen to audio track 12A and, using a mouse, keyboard or other
manual input device of the computer, physically tap the rhythmic beats of
audio track 12A into the computer. The resulting beat track 12C,
containing sequentially numbered beat markers and corresponding SMPTE
addresses, is then recorded onto another track of the working tape along
with audio tracks 12A and time code track 12B. Alternately, if time code
track 12B is formated according to the MIDI protocol, track 12C will
contain a sequence of MIDI codes corresponding to the sequence of times at
which rhythmic beats occur during the audio track 12A.
Next, the MIDI data of the synthesized performance is generated, as notated
by steps 26-30. Using a personal computer running a commercially available
MIDI software package, such as "Professional Performer" by Mark of the
Unicorn, Inc., Cambridge, Mass. 02142, and a keyboard or other MIDI device
coupled with the computer, an instrumental part is accurately performed
from a copy of the musical score. For example, instrumental part 52 of
score 40 will be played in real time at the MIDI keyboard to qenerate a
"channel" of MIDI data representing the pitch and rhythmic information of
instrumental part 52. The MIDI software in most cases, enables the
instrumental part to be played in real time at a tempo which is slower
than that designated on the score, thereby ensuring an accurate
performance. This step, represented by step 26, is repeated for
instrumental parts 54-58, thereby generating a part by part MIDI
representation of score 40 in which each instrumental part is stored on a
separate MIDI channel in the computer memory.
After the pitch and rhythmic information of each instrumental part has been
entered into a separate MIDI channel, additional MIDI information is added
using the computer keyboard. As designated by step 28 of FIG. 3,
interpretative parameters, such as dynamic changes, instrumental tone, and
tempo variations, are added to each MIDI channel using the editing
facilities of the MIDI software and computer.
Next, as designated by step 30, each MIDI channel representing an
instrumental part is assigned to a synthesized "voice" or sampled sound
which the MIDI channel will trigger to simulate the sound of the
instrument of the originally recorded performance.
The Professional Performer software, or an analogous MIDI software package,
further numbers each bar and beat of score 40 as well as storing data for
each MIDI channel which can be used to create a visual copy of the score
such as that shown in FIG. 5.
The resulting MIDI track or tracks 12D, containing a complete MIDI
representation of score 40, including separate MIDI channels for each
instrumental part, is stored in the computer memory.
In an alternate, although more cumbersome, method, all MIDI data continued
in track(s) 12D, including the pitch and rhythmic information of each MIDI
channel, may be entered visually at a computer keyboard via the MIDI
software package. This method is preferable for those musicians who are
unaccustomed to playing keyboard instruments.
Next, as indicated by step 32, user information relating to the data on
tracks 12A-D is entered through the computer and stored in memory. The
user information includes the disc number, the title number of the piece,
the title of the piece, the composer, names and numbers of the movements
of the piece, total time of the piece, number of the bars for each
movement, etc. This data is recopied onto yet another track of the working
tape as track(s) 12E along with track(s) 12D and tracks 12A-C.
Finally, once all of the information contained on tracks 12A-E is entered
onto a working tape, this information is written onto disc 12 using a
conventional compact disc writing technique, as indicated by step 34. For
simplification, the tracks 12A-E of disc 12 have been partitioned
conceptually according to the type of data represented therein. It would
be obvious to one reasonably skilled in the art that the actual
distribution of data to disc tracks may vary with applications and is a
matter of design choice, as is the medium in which this data will be
recorded. Typically, to facilitate real time alignment of audio track 12A
with MIDI track(s) 12D, time code track 12B and beat track 12C will be
interpolated with audio track 12A into a single track in the final format
of disc 12.
ROM cartridge 14, shown in FIG. 1, contains a plurality of instrumental
sounds or audio samples which have been stored digitally. The audio
samples are typically created by playing an acoustic instrument into a
device which digitally samples the tone of the instrument and stores the
sampled data in a computer memory. This sample tone forms a model of the
instrumental sound which is triggered by the data in a MIDI channel. Each
MIDI channel contained in track 12D of disk 12 is assigned to one audio
sample in ROM cartridge 14. When indicated by the data in a MIDI channel
in track 12D, an audio sample from cartridge 14 is converted by the MIDI
protocol and circuitry in system 80, which includes digital-to-analog
converters, into a audio tone which simulates the designated acoustic
instrument named in the corresponding instrumental part of score 40. The
audio samples may be stored digitally in ROM cartridge 14 or any device
which allows storage and MIDI access of digital audio samples, including
magnetic and optical disks of varying sizes. A ROM cartridge suitable for
use with the present invention is commercially available from Kurzweil
Music Systems, Inc., 411 Waverly Oaks Road, Waltham, Mass. 02154-6484.
THE MUSIC ANALYSIS SYSTEM
Referring to FIG. 1, a block diagram is shown of music analysis system 80.
System 80 is, preferably, a microprocessor based system comprising special
function, integrated circuit (IC) chips and special MIDI circuitry.
Music analysis system 80 can be conceptionally divided into the central
processor unit 82, memory subsystem 84, user interface subsystem 86,
peripheral input/output controller 88, signal processing subsystem 90, and
a plurality of buses and signal paths interconnecting these subsystems.
In the preferred embodiment, central processing unit (CPU) 82 is comprised
of a commercially available microprocessor, such as the Model 80286 16-bit
microprocessor, produced by Intel Corporation, Santa Clara, CA 95051. CPU
82 further comprises any supporting IC chips necessary to help the
microprocessor interface with the other elements of system 80. Such
additional support chips include, but are not limited to, a clock
generator IC, a bus controller IC, and interrupt controller IC and various
transceiver and latch IC's. These additional support chips are also
available from Intel Corporation, and are specifically compatible with the
Model 80286 microprocessor CPU 82 is connected to memory subsystem 84 by a
24-bit address bus 91 and a 16-bit data bus 92.
Memory subsystem 84 is comprised of random access memory (RAM) 81 and read
only memory (ROM) 83. Address bus 91 supplies addresses from CPU 82 to RAM
81 and ROM 83, while data accessed at these addresses is supplied to CPU
82 and the other elements of system 80 over data bus 92. In the preferred
embodiment, RAM 81 is comprised of a plurality of commercially available
RAM IC chips, the size and configuration being left to the designer's
discretion. RAM 81 further includes any additional non-memory circuitry,
such as a memory controller IC, necessary for implementing and interfacing
RAM 81 with the other elements of system 80. Likewise, ROM 82 is comprised
of a plurality of commercially available ROM IC chips, the size and
arrangement being left to the desiqner's discretion. ROM 82, similarly,
includes any non-memory circuitry such as a memory controller IC and bus
interface registers necessary for successfully interfacing ROM 83 with the
other elements of system 80.
User interface subsystem 86 is comprised of a keyboard interface logic 85A
and display logic 87. In the preferred embodiment, keyboard 85 (FIG. 4) is
comprised of a plurality of push button and rocker type switches or keys
and the control circuitry required for interfacing the keyboard signals
with ROM 83 and CPU 82. Each key of keyboard 85 is used to initiate a
function which is executed by the various elements of system 80. FIG. 4
illustrates a typical arrangement of the keys comprising keyboard 85,
including a 9-digit numeric keypad 154. In an alternate embodiment, a
conventional alpha-numeric keyboard may be interfaced with input/output
controller 88 and data bus 92 for processing of user commands by CPU 82.
In the preferred embodiment, display logic 87 is comprised of one or more
liquid crystal displays, as shown in FIG. 4. The main display 87A is
preferably a back lit LCD display with a 640.times.320 resolution. The
smaller display 87B is also a back-lit LCD display with a 180.times.80
resolution Display logic 87 further includes the necessary timing and
drive circuitry necessary to generate the display and interface the
display with data bus 92, including display buffer memory. It is obvious
to one reasonably skilled in the art that main display 87A may be further
divided into a plurality of smaller LCD displays or the display apparatus
itself may be implemented with a different technology such as an
electroluminescent screen or a CRT video display monitor. As shown in
FIGS. 1 and 4, user interface subsystem 86 further comprises control panel
89, on which keyboard 85 and displays 87A B are located, as well as a
variety of manual input controls to signal processing subsystem 90.
Signal processor subsystem 90 is comprised of CD circuitry 93, MIDI
circuitry 94, amplifier 96, mixer 98, equalizer 100, and reverberation
unit 102. MIDI circuitry 94 is comprised of dedicated circuitry, including
digital-to analog converters, necessary to convert the MIDI data supplied
over bus 92 into analog signals. The exact requirements of MIDI circuitry
94 are defined by the MIDI protocol and are within the acknowledge of one
reasonably skilled in the field of electronic music circuits. Accordingly,
a detailed description of the MIDI circuitry is beyond the scope of this
document. MIDI circuitry 94 contains a quantity of ROM memory, similar to
ROM 83, which contains a copy of commercially available MIDI software,
such as "Professional Performer" by Mark of the Unicorn, Inc. MIDI bus 97
provides a means for connecting MIDI instrument 99, preferably a keyboard
or other instrument with a MIDI interface, to MIDI circuitry 94. The MIDI
software stored in MIDI circuitry 94 formats the MIDI data entered via
instrument 99 and bus 97, according to the MIDI protocol and sends it to
RAM 81 for storage with an existing MIDI score as explained hereinafter.
MIDI circuitry 94 further includes synchronizaticn circuitry capable of
synchronizing the MIDI and SMPTE data read from disc. Such MIDI to SMPTE
synchronizing circuitry is available commercially in a device known as the
"Jam Box" from South Worth Music Systems, Inc., 91 Ann Lee Road, Harvard,
Mass. 01451.
In an alternate embodiment, MIDI circuitry 94 may include SMPTE to SMPTE
synchronizing circuitry or MIDI to MIDI synchronizing circuitry in
addition to or in place of the existing MIDI to SMPTE synchronizing
circuitry.
MIDI circuitry 94 further includes a commercially available National
Television Standards Committee (NTSC) signal generating circuit for
converting MIDI data into a complete video signal capable of driving a
video display device. Such a circuit enables the MIDI data to be viewed
visually in the form of a musical score as shown in FIG. 5. MIDI circuitry
94 interfaces with ROM cartridge 14 containing the audio samples via I/0
controller 88 and data bus 92.
The audio signals generated by MIDI circuitry 94, representing the
synthesized performance or unsolved, and any soloed instruments, as
explained hereinafter, are transmitted to amplifier 96 over audio bus 109A
and 109B, respectively.
The audio signals carried by buses 109A-B are processed by amplifier 96,
equalizer 100, reverberation unit 102 and coupled with their respective
stereo audio bus in mixer/amplifier 98. Amplifier 96 preferably is
comprised of a plurality of internal IC preamplifiers. Amplifier 96
further contains a line level input 104A and a conventional cannon jack
input 104B for accepting a line level or microphone level signal,
respectively. These inputs allow external signals to be amplified for
subsequent modification and mixing by signal processor subsystem 90. The
audio signals amplified by amplifier are then sent to equalizer 100.
Equalizer 100, in the preferred embodiment, is a 5-band graphic equalizer,
with the center frequencies of the bands occurring at 60 Hz, 200 Hz, 600
Hz, 2 KHz and 10 KHz, for example. Preferably the level of gain or
attenuation of each band is at least +/- 10 dB. It is obvious to one
reasonably skilled in the art that the number of bands of the equalizer,
the center frequencies of the bands and the level of gain or attenuation
of each band is left to the desiqner's discretion. The gain or attenuation
levels of each band of equalizer 100 are controlled by a number of
conventional sliding potentiometers 100A-E, as shown in the control panel
89 of FIG. 4. After the audio signals generated by MIDI circuitry 94 are
amplified by amplifier 96 and modified by equalizer 100, they are
processed by reverberation unit 102 which is connected to equalizer 100.
Reverberation unit 102 is preferably a digital processor based unit having
a plurality of pre programmed settings for simulating the ambient
acoustics of varying sized interiors. Typically, these settings would be
proqrammed for no reverberation, i e, a "dry" signal, or to simulate rooms
or halls having increasing amounts of reverberation, i.e, a "wet" signal.
A plurality of push button switches 102A-D electrically coupled to
reverberation unit 102, enables the user to select the desired amount of
reverberation from control panel 89.
Compact Disc (CD) circuitry 93 contains conventional, circuitry, such as
digital to analog converter, and amplifiers, for conversion of the data
representing the recorded performance into an analog audio signal. Such
circuitry is within the knowledge of one reasonably skilled in the field
of audio electronics and will not be described in detail in this document.
The digital data representing the recorded performance stored on disc 12
of optical disc player 108 is supplied to CD circuitry 93 via bus 106, and
input/output controller 88, and bus 107 as shown in FIG. 1.
After reverberation unit 102, the audio signals from tho synthesized
performance, both soloed and non soloed, are sent to an internal stereo
summing amplifier of mixer/amplifier 98 along with the audio signal of the
recorded performance from CD circuit 93 via bus 95. Mixer/amplifier 98
which contains three separate stereo audio buses, for the recorded
performance, synthesized performance and soloed instruments, respectively,
mixes the audi | | |
