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Description  |
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BACKGROUND OF THE INVENTION
This invention relates to an electronic musical instrument equipped with an
automatic bass/chord performance function.
An automatic bass/chord performance function by which bass tones and chord
tones are produced automatically in accordance with a predetermined rhythm
pattern by depressing the keys corresponding to the desired chord in a
keyboard for chord performance (such as a lower keyboard), is well known
in the art. In this kind of electronic musical instrument equipped with an
automatic bass/chord performance function, the player must manage the
chord progression (changes of chords according to measures) by playing the
lower keyboard with his left hand. If the chord progression can be done
automatically, the player does not need to use his left hand for the chord
progression. Thus, all the players have to do is to play the melody.
Accordingly, easy playing is available to all players, especially to
beginners.
SUMMARY OF THE INVENTION
Accordingly, an object of this invention is to provide an electronic
musical instrument which performs automatically the chord progression in
automatic bass/chord performance function.
According to this invention, a plurality of chords are stored in advance
and stored chords are read out in accordance with progression of music for
an automatic bass performance and an automatic chord performance.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
FIG. 1 is a block diagram indicating the example of the automatic
performance device according to this invention;
FIG. 2 is a circuit showing the detail of the bass region of the lower
keyboard in FIG. 1;
FIG. 3 is a block diagram showing the detail of the chord tone data
producing circuit in FIG. 1;
FIG. 4 is a block diagram showing the detail of the data converter in FIG.
3;
FIG. 5 is a block diagram of the OR circuit group in FIG. 3;
FIG. 6 is a block diagram showing another detailed example of the chord
note data producing circuit in FIG. 1;
FIG. 7 is a block diagram showing only changed portion in another example
according to this invention.
DETAILED DESCRIPTION OF THE INVENTION
The embodiment shown in FIG. 1 is arranged such that chord progression in
the automatic bass/chord performance is realized either automatically or
manually.
In FIG. 1, the upper keyboard 1 is for playing melodies and not related to
the automatic bass/chord performance function. The signals corresponding
to the depressed keys are delivered from the upper keyboard 1 and applied
to a tone generator 2. In the tone generator 2, musical tone signals of
frequencies corresponding to the respective pitches of the depressed keys
are produced and then a suitable tone color (for example, a flute tone
color) is given to the musical tone signals. These musical tone signals
outputted from the tone generator 2 are applied to sound system 3, where
the tones are sounded audibly.
The lower keyboard 4 is for playing melodies and conducting chord
progression in the automatic bass/chord performance. In this embodiment,
the lower keyboard 4 is divided into two regions: treble (higher side)
region 4a and bass region (lower side) 4b. The treble region 4a is used to
play melodies, while the bass region 4b is used for chord performance. The
treble region 4a delivers, in the same way as the upper keyboard, signals
corresponding to the depressed keys, and these signals are applied to the
tone generator 5. Then, based on these signals, the tone generator 5
produces musical tone signals of frequencies corresponding to the
respective notes of the depressed keys, and a suitable tone color (for
example, a string tone color) is given to these musical tone signals.
These signals are sent to sound system 3 and then sounded audibly.
The bass region 4b of the lower keyboard 4 is the section conducting chord
performance. It delivers out signals which indicate notes constituting a
chord (hereinafter called chord constituent notes) automatically or by
manual operation. In other words, as is shown in FIG. 2, the bass region
4b is provided with a power source line 6 which is supplied with signal
"1"; output lines 7C, 7C.music-sharp., . . . , 7B which correspond to
respective musical notes (C, C.music-sharp., . . . , B); diodes 8C,
8C.music-sharp., . . . , 8B which are connected between the power source
line 6 and the output lines 7C, 7C.music-sharp., . . . , 7B; and key
switches 9C, 9C.music-sharp., . . . , 9B which are turned on when the
respective associated keys are depressed. Signal "1" is applied to the
output line (among 7C, 7C.music-sharp., . . . , 7B) which corresponds to
the note of the key which is being depressed in this bass region.
Furthermore, in parallel to the circuits respectively having the
above-mentioned diodes 8C, 8C.music-sharp., . . . 8B and switches 9C,
9C.music-sharp., . . . , 9B, there are respectively connected circuits
respectively provided with diodes 10C, 10C.music-sharp., . . . , 10B and
gates 11C, 11C.music-sharp., . . . , 11B (for example, FET gates). These
latter circuits are connected between the power source line 6 and the
output lines 7C, 7C.music-sharp., . . . , 7B, respectively. Here, the
gates 11C, 11C.music-sharp., . . . , 11B are turned on in response to the
outputs (signals which represent chord constituent notes in the automatic
chord progression) of a chord note data producing circuit 12 as described
later, and the signal "1" is produced on the output lines (among 7C,
7C.music-sharp., . . . , 7B) corresponding to the chord constituent notes
in the automatic chord progression.
The signals, which indicate the chord constituent notes, are outputted from
the bass region 4b and applied to the tone generator 15 in FIG. 1. In this
tone generator 15, musical tone signals having frequencies corresponding
to the chord constituent notes are produced respectively and a suitable
tone color (for example, the tone color of a brass instrument) is given to
these tone signals. Then the timings of the tone production are controlled
by a beating pulse PC as described later and then the signals are led to
the sound system 3. In this way, the chord tones are sounded from the
sound system 3. Furthermore, the signals which represent the chord
constituent notes and are delivered from the bass region 4b are
simultaneously applied to the root note detector circuit 16 wherein the
root note of the chord being depressed is detected. When the root note is
detected, a data Df indicating the root note is applied to an adder 17.
Then bass pattern data Ds which are produced by a pattern producing
circuit 60 as described later, are added to the data Df which indicates
the above root tone, by the adder 17 to produce root note data, which in
turn is applied to the tone generator 18. Here a brief explanation about
the bass pattern data Ds is made.
In automatic bass performance, the chord constituent notes are generally
produced one at a time and one after another as bass tones in accordance
with the desired rhythm. In order to produce also the tones of the notes
other than the root note (hereinafter referred to as subordinate notes)
among the chord constituent notes, as the bass tones, these subordinate
notes must be formed based on the root note. The data for also generating
subordinate notes are the bass pattern data Ds. The bass pattern data Ds
are the data which indicate which one from among the chord constituent
notes should be generated at respective tone production timings of the
bass tones. Therefore, the data Ds indicate numerically the respective
degrees of the chord constituent notes with respect to the root note.
At the tone generator 18, musical tone signals are generated on the basis
of the inputted bass tone data, and tone color of the bass tones is given
to the generated musical tone signals. Tone production timings of the
musical tone signals are controlled in response to key-on pulses KONP as
explained later and the signals are applied to the sound system 3 wherein
bass tones are sounded audibly.
In FIG. 1, the chord note data producing circuit 12 is a circuit provided
with a memory which stores several kinds of chord progression patterns. A
chord progression designation switch 20 is a switch which permits the
player to select one chord progression pattern from among said several
kinds of chord progression patterns. When the signal generated according
to the operation of that switch 20 is applied to the chord note data
producing circuit 12 as an address signal, the addressed chord progression
pattern is read out. A tonality designation switch 21 is a switch which
selectively designates the tonality of the chord tones to be produced in
accordance with the selected chord progression. In other words, in this
example, in order to lessen the capacity of the memory which stores the
chord progression patterns, the chord name data (for example, C, Am,
G.sub.7, etc.) are not stored just as they are, but the data (hereinafter
called chord degree data) is stored in a form such that the tonality is
not included in the chord name data. Then the tonality is added to the
chord degree data in forming the chord note data. Here, the chord degree
data is such a data (for example, I, IIm, V.sub.7 (a symbol which has no
suffix indicates a major triad)) that is obtained by combining the data
(for example, the first degree (I), the second degree (II), the fifth
degree (V)) (hereinafter called degree data) which shows the degree of the
root note of the chord in the musical scale of the performed tonality and
the data (for example, major triad (M), minor triad (m), dominant seventh
(7), etc.) (hereinafter called chord type data) which shows the chord
type. It should be noted that a term "tonality" is used to mean a note
name or "key" in this specification to prevent confusion with a key in a
keyboard. The chord degree represents the position in the musical scale of
the chord root note with respect to a particular, separately designated
tonality or note name.
Concretely speaking, the addition of the tonality to the above noted chord
degree data is performed as shown below. Firstly, the chord progression
pattern which is stored in the memory 30 is in the chord degree data form
such as, for example.
I.fwdarw.VIm.fwdarw.IIm.fwdarw.V.sub.7.
Then, with respect to the chord progression pattern, when the tonality of C
is designated, each of the chord degree data I, VI, II, V now corresponds
to the chord of C, the chord of A, the chord of D and the chord of G
respectively so that the chord note data are outputted from the chord note
data producing circuit 12 in the chord progression pattern of
C.fwdarw.Am.fwdarw.Dm.fwdarw.G.sub.7.
A measure counter 22 reads out respective chord note data, measure by
measure, from the chord note data producing circuit 12, according to the
above noted chord progression pattern. This measure counter 22 is driven
based on the tempo pulse TP from the tempo oscillator 23. In other words,
the tempo oscillator 23 generates the tempo pulse TP having a
predetermined period and supplies the pulse to an address generator 24.
The address generator 24 counts this tempo pulse TP and produces one pulse
Ci (measure pulse) every time the counter value reaches a number
equivalent to the time length of one measure. In the measure counter 22,
this measure pulse Ci is counted and count value thereof is outputted as
data Dc (measure number data) showing the number of measures. The measure
number data Dc is supplied to the chord note data producing circuit 12 as
an address signal so that the chord degree data of the designated chord
progression pattern are read out sequentially, measure by measure.
The detailed example of the chord note data producing circuit 12 is shown
in FIG. 3.
In FIG. 3, a chord progression pattern producing circuit 30 is a memory
circuit (ROM) which stores various progression patterns
##STR1##
of sequential combination of the chord degree data. In this chord
progression pattern producing circuit 30, one chord progression pattern is
designated according to the operation of the chord progression designating
switch 20. Each chord degree data of the designated chord progression
pattern is read out based on the measure number data Dc at every one
measure.
The chord degree data is, as explained earlier, the data which includes
degree data and chord type data, and in the circuit 30, these degree data
and chord type data are outputted on separate lines. In this example,
there are 5 types of chord: major triad (M), minor triad (m), dominant
seventh (7), minor seventh (m7) and major sixth (6), and a corresponding
output line 32 (32M, 32m, 32.sub.7, 32m.sub.7, 32.sub.6) is provided for
each chord type. Therefore, signal 1 is outputted to the output line which
corresponds to the chord type from the circuit 30. The degree data is as
shown in Table 1.
TABLE 1
______________________________________
Degree
Degree data
______________________________________
VII 1011
VI.music-sharp.
1010
VI 1001
V.music-sharp.
1000
V 0111
IV.music-sharp.
0110
IV 0101
III 0100
II.music-sharp.
0011
II 0010
I.music-sharp.
0001
I 0000
______________________________________
The adder 31 changes the degree data outputted from the circuit 30 into
data of the note name according to the tonality designated by the tonality
designation switch 21. In this embodiment, the data (hereinafter called
the tonality data) according to the tonality designated by the tonality
designation switch 21 is produced and tonality data is added to the degree
data, thus converting it into data representing the actual note name. The
tonality data and also the note name data (i.e. a data which represents
the note name) are such as shown in Table 2.
TABLE 2
______________________________________
Tonality or Tonality Data or
Note Name Note Name Data
______________________________________
B 1011
A.music-sharp. 1010
A 1001
G.music-sharp. 1000
G 0111
F.music-sharp. 0110
F 0101
E 0100
D.music-sharp. 0011
D 0010
C.music-sharp. 0001
C 0000
______________________________________
In the case that the note name data is determined as shown in Table 2, the
output data of adder 31 for each degree and the note names corresponding
to output data are as shown in the column a of Table 3 when the tonality
is designated as F (the tonality data is 0101).
TABLE 3
______________________________________
a.circle. b.circle.
Output Output
data of data of
adder (note conver- (note
Degree (data) 31 name) ter 32 name)
______________________________________
VII (1011) 10000 (none) 00100 (E)
VI.music-sharp.
(1010) 01111 (none) 00011 (D.music-sharp.)
VI (1001) 01110 (none) 00010 (D)
V.music-sharp.
(1000) 01101 (none) 00001 (C.music-sharp.)
V (0111) 01100 (none) 00000 (C)
IV.music-sharp.
(0110) 01011 (B) 01011 (B)
IV (0101) 01010 (A.music-sharp.)
01010 (A.music-sharp.)
III (0100) 01001 (A) 01001 (A)
II.music-sharp.
(0011) 01000 (G.music-sharp.)
01000 (G.music-sharp.)
II (0010) 00111 (G) 00111 (G)
I.music-sharp.
(0001) 00110 (F.music-sharp.)
00110 (F.music-sharp.)
I (0000) 00101 (F) 00101 (F)
______________________________________
As in the above, adder 31 converts the degree data into note name data for
the designated tonality. However, it can be seen from column a in Table
3 that there are some situations where the output of the adder 31 does not
correspond to any of note name. This is because the note name can be
indicated by the number within the range from "0000(note C)" to "1011(note
B)" but the sum value from the adder 31 may become above such a range.
Accordingly, when the sum is "1100" or above, the value must be corrected
into the correct note name data. In other words, since above the note B
are repeated the note C, the note C.music-sharp., . . . , B and over
again, it is preferable that sum values "1100" and above are converted to
data corresponding to the note of C, C.music-sharp., . . . , B
respectively.
In FIG. 3, the data converter 32 performs such a conversion of the data.
Each of the conversions is such that the relation between the input data
(the 5 bit data Q.sub.5 Q.sub.4 Q.sub.3 Q.sub.2 Q.sub.1) and the output
data (the 4 bit data Q.sub.4 ' Q.sub.3 ' Q.sub.2 ' Q.sub.1 ') become as
shown in Table 4.
TABLE 4
______________________________________
Input data (note Output data (note
Q.sub.5
Q.sub.4
Q.sub.3
Q.sub.2
Q.sub.1
name) Q.sub.4 '
Q.sub.3 '
Q.sub.2 '
Q.sub.1 '
name)
______________________________________
1 0 1 1 0 (none)
1 0 1 0 (A.music-sharp.)
1 0 1 0 1 (none)
1 0 0 1 (A)
1 0 1 0 0 (none)
1 0 0 0 (G.music-sharp.)
1 0 0 1 1 (none)
0 1 1 1 (G)
1 0 0 1 0 (none)
0 1 1 0 (F.music-sharp.)
1 0 0 0 1 (none)
0 1 0 1 (F)
1 0 0 0 0 (none)
0 1 0 0 (E)
0 1 1 1 1 (none)
0 0 1 1 (D.music-sharp.)
0 1 1 1 0 (none)
0 0 1 0 (D)
0 1 1 0 1 (none)
0 0 0 1 (C.music-sharp.)
0 1 1 0 0 (none)
0 0 0 0 (C)
0 1 0 1 1 (B) 1 0 1 1 (B)
0 1 0 1 0 (A.music-sharp.)
1 0 1 0 (A.music-sharp.)
0 1 0 0 1 (A) 1 0 0 1 (A)
0 1 0 0 0 (G.music-sharp.)
1 0 0 0 (G.music-sharp.)
0 0 1 1 1 (G) 0 1 1 1 (G)
0 0 1 1 0 (F.music-sharp.)
0 1 1 0 (F.music-sharp.)
0 0 1 0 1 (F) 0 1 0 1 (F)
0 0 1 0 0 (E) 0 1 0 0 (E)
0 0 0 1 1 (D.music-sharp.)
0 0 1 1 (D.music-sharp.)
0 0 0 1 0 (D) 0 0 1 0 (D)
0 0 0 0 1 (C.music-sharp.)
0 0 0 1 (C.music-sharp.)
0 0 0 0 0 (C) 0 0 0 0 (C)
______________________________________
It will be understood from Table 4 that the data converter 32 performs the
conversion according to value of the 3 bits of the input data Q.sub.5
Q.sub.4 Q.sub.3. Concretely speaking, as is shown in Table 5, when the
values of Q.sub.5 Q.sub.4 Q.sub.3 before the conversion is "101", the
values of Q.sub.4 Q.sub.3 are inverted to become "10" and when the values
of Q.sub.5 Q.sub.4 Q.sub.3 are "100", the number "1" is set in Q.sub.3 so
that after conversion Q.sub.4 ' Q.sub.3 ' become "01". When the values of
Q.sub.4 Q.sub.3 before conversion are "11", the values of Q.sub.4 Q.sub.3
are reversed so that the values of Q.sub.4 ' Q.sub.3 ' after conversion
become "00". Besides the situations, the data is passed through as is
without conversion.
TABLE 5
______________________________________
Before After
conversion conversion
Q.sub.5 Q.sub.4 Q.sub.3 Q.sub.4 '
Q.sub.3 '
______________________________________
1 0 1 1 0
1 0 0 0 1
1 1 0 0
______________________________________
An example of data converter 32 which performs the conversion as shown
above is shown in FIG. 4. In FIG. 4, the drawing of the input lines of the
AND circuits 43, 44 and 45 has been simplified. This means that from among
the bit outputs of the adder 31, the bit signals which are inputted to the
adders 43, 44, 45 are shown with circles at the point of intersection with
input lines of and the circuits 43, 44, 45. In other words, the input
signals Q.sub.3 and Q.sub.4 are applied to the AND circuit 43, input
signals Q.sub.5, Q.sub.3 and Q.sub.4 which is obtained by inverting
Q.sub.4 through the inverter 46 are applied to the AND circuit 44; and
input Q.sub.5 and input signals Q.sub.4 and Q.sub.3, which are obtained
with the inversions of inputs Q.sub.4 and Q.sub.3 through the inverter 46,
are added to the AND circuit 45. Then the output of the AND circuits 43
and 44 are collected at OR circuit 48 and are applied to one input of each
of EXCLUSIVE OR circuits 49 and 50. To the other input of these EXCLUSIVE
OR circuits 49 and 50, the outputs Q.sub.4 and Q.sub.3 of the adder 31 are
applied respectively. The output of EXCLUSIVE OR circuit 49 is outputted
from conversion device 32 as the output Q.sub.4 ' of the data converter 32
and the outputs of EXCLUSIVE OR circuit 50 and the AND circuit 45
outputted from converter 32 through an OR circuit 51 as output Q.sub.3 '.
Accordingly, when the input Q.sub.5 Q.sub.4 Q.sub.3 of the data converter
32 is "101", the output of the AND circuit 44 becomes "1" so that the
output Q.sub.4 ' Q.sub.3 ' becomes "10". When the output Q.sub.5 Q.sub.4
Q.sub.3 is "100", the output of AND circuit 45 becomes "1" and is
outputted through the OR circuit 51 so that the output Q.sub.4 ' Q.sub.3 '
becomes "01". Furthermore, when the input Q.sub.4 Q.sub.3 is "11", the
output of the AND circuit 43 becomes "1" so that the output Q.sub.4 '
Q.sub.3 ' becomes "00". In the above way, the conversion shown in the
Table 4 is performed. The data in column b in the Table 3 shows data
obtained by converting data in column a in the Table 3 in the same way
as above.
The data (Q.sub.4 '-Q.sub.1 ') which is outputted from the data conversion
device 32, as the note name data representing the name of the root note of
the chord tone, is applied to the decoder 37 (FIG. 3). Furthermore, this
note name data is applied to the adder 33 and 34 and is used to form two
subordinate notes. As the degrees of the subordinate notes are definite
according to the type of chord (major triad (M), minor triad (m), dominant
seventh (7) etc.), it is necessary that the value corresponding to the
interval of each degree from the root is added to the note name data of
the root note, in order to form the note name data of the subordinate
notes based on the note name data of the root note. Table 6 shows relation
between types of chord and the note degrees of the root note and two
subordinate notes constituting a chord. In Table 6, the root notes are
shown by O and the subordinate notes by .DELTA. and .quadrature.. The
number which is written in parentheses next to the number showing the note
degree is a number which shows how far the note is separated from the root
note among the 12 notes C-B. When the subordinate notes are formed on the
root note, these numbers are respectively added to the note name data of
the root note.
TABLE 6
______________________________________
Type
of Note degree
chord 1.degree.
3b.degree. (3)
3.degree. (4)
5.degree. (7)
6.degree. (9)
7b.degree. (10)
______________________________________
major triad
(M) O .increment.
.quadrature.
minor triad
(m) O .increment. .quadrature.
dominant
seventh (7)
O .increment. .quadrature.
minor
seventh (m7)
O .increment. .quadrature.
sixth (6)
O .increment.
.quadrature.
______________________________________
The adder 33 and 34 add each of the numbers representing the distances of
the note degrees of the two subordinate notes from the root note (in other
words, the numbers written in parentheses in the note degree column of
Table 6) to the note name data of the root note to form the note name data
of each of the two subordinate notes. Concerning the subordinate notes
which are shown in Table 6 by .DELTA. (hereinafter called the first
subordinate note), since in this example they are notes being apart from
the root note by a minor third interval or more (refer to Table 6), the
adder 33 shown in FIG. 3 always adds +3 and the deficiencies are further
added depending on the types of chord. For example, in the case of major
triad (M), the degree of the first subordinate note is a major third and
the number to be added is +4, and this is different from +3 by +1, the
signal "+1" brought from the major output line 32M is added to the adder
32. In the same way, in the chords of dominant seventh (7) and sixth (6),
the degree of the first subordinate note is a fifth and the number to be
added is "7, and thus, as this is different from +3 by +4, a value "+4" is
added to the adder 33 based on a "1" signal led through the OR circuit 41
from the output lines 32.sub.7 and 32.sub.6. In the cases of minor triad
(m) or minor seventh (m7) chords, the degree of the first subordinate note
is a minor third and the number to be added is +3, but as the difference
with the +3 is 0, the "1" signal from the output lines 32m, 32m.sub.7 is
not used for addition.
As the subordinate notes shown by .quadrature. in Table 6 (hereinafter the
second subordinate notes) are notes being apart from the major root note
by a fifth interval or more in this example, +7 is always added to the
adder 34 and the deficiencies are further added, depending on the types of
chord. For example, in the case of sixth (6), the degree of the second
subordinate note is a major sixth and the number to be added is "9, but as
the difference from +7 is +2, +2 is further added to the adder 34 based on
the "1" signal from the sixth output line 32.sub.6. In the case of
dominant seventh and minor seventh, the degree of the second subordinate
note is minor seventh and the number to be added is +10, but as the
difference from +7 is 3. This "3" is added to the adder 34 based on the
signal "1" led through the OR circuit 42 from the previously mentioned
output lines 32.sub.7 and 32m.sub.7. In the case of major triad (M) and
minor triad (m) the degree of the second subordinate note is fifth and the
number to be added is +7, but as the difference from +7 is 0, the "1"
signals from the output lines 32M and 32m are not applied to the adder 34.
As in the above, the note name data indicating the first subordinate note
and the second subordinate note are outputted from adders 33 and 34.
As there are cases where in the similar way as in the situation with
respect to the adder 31, the sum values of the adders 33 and 34 do not
correspond to the note names to which they are supposed to correspond, the
data converters 35 and 36 designed in the same manner as the data
converter 32, are utilized to convert the sum values to appropriate
values.
The note name signals of the first and second subordinate notes outputted
from the data converters 35 and 36 are decoded at decoders 38 and 39, and
then are applied to an OR circuit group 40. The note name data of the root
note outputted from the data converter 32 is decoded at decoder 37, and
then is applied to the OR circuit group 40. The OR circuit group 40 is to
deliver out the signals of the same note name in common among the output
lines of decoders 37, 38, 39. For example, the OR circuit group 40
comprises a plurality of OR circuits 52C-52B to each input of which the
output lines of the corresponding note names of the decoders 37, 38, 39
are connected as shown in FIG. 5.
The note name signals which indicate the chord constituent notes (the root
note and the first and second subordinate notes) outputted from the OR
circuit group 40, are applied to the gates 11C, 11C.music-sharp., . . . ,
11B (refer to FIG. 2) which are included in the bass region 4b of the
lower keyboard 4, and a signal "1" is led to the output line (7C,
7C.music-sharp., . . . 7B) corresponding to that note name. The signals
which indicate the chord constitutent notes outputted from the bass region
4b are applied to the tone generator 15, wherein a suitable tone color
(here a brass tone color) is imparted. Furthermore, after a suitable
rhythm has been given based on the beating pulses PC which are outputted
from pattern producing circuit 40, explained later, in correspondence with
the production timing of the chord tones, the signals are directed to the
sound system 3. In this way, in response to the output from the chord note
data producing circuit 12, the chord tones are generated from the sound
system 3.
The signals which indicate the chord constituent notes outputted from the
bass region 4b of the lower keyboard 4, are applied to the root note
detector circuit 16 wherein the root note is detected. The data Df
representing the detected root note is applied to the adder 17. The
pattern producing circuit 60 is a circuit which stores the rhythm patterns
of the bass tones. Based on the stored rhythm pattern, short pulses
(key-on pulses) KONP are delivered out. For example, signals "1" are
stored at positions of the memory corresponding to the tone production
timings in accordance with the rhythm pattern, and thereafter are read out
by an address signal from address generator 24, and is shaped into a short
pulse so that the key-on pulse KONP is obtainable.
The pattern producing circuit 60 also produces the bass pattern data Ds
every time a key-on pulse KONP is generated. This data Ds is then applied
to the adder 17 so as to modify the root note data outputted from the root
note detector circuit 16. For example, where the chord constituent notes
of the chords in the chord progression pattern selected by the chord
progression designation switch 20, are produced one after another in one
measure, it is advisable to do the following. Now, assume that, for
example, from among the chords constituting the chord progression pattern
selected by chord progression designation switch 20, the chord "Dm" was
designated based on the measure number data Dc of the measure counter 22.
Then the output data Df of root note detector circuit 16 is "0010"
indicating the note D. As it is possible to form the two subordinate notes
constituting the m (minor) chord by adding +3 (in binary digits "0011")
and +7 (in binary digits "0111") respectively to the note name data of the
root note data (refer to table 6), the pattern generating circuit 60
delivers out no signal (the bass pattern data Ds is "0000") at the timing
of the first key-on pulse KONP but let the adder 17 deliver "0010", that
is, the note name data of D. Then the pattern generation circuit 60
outputs "0011" as the bass pattern data at the timing of the second key-on
pulse KONP so as to let the adder 17 deliver out "0101", that is, the note
name data of F. It also outputs "0111" as the bass pattern data at the
timing of the third key-on pulse KONP so as to let the adder 17 deliver
out "1001", that is, note name data of A. In this way, the musical tone
signals of the bass tones are produced one after another in accordance
with the production timings of the key-on pulses KONP from the tone
generator 18.
The pattern generation circuit 60 generates beating pulses PC which
determine the production timings of the chord tones. These beating pulses
can be obtained, for example, by the similar method as that of production
of the above noted key-on pulse KONP. Namely, signals "1" are stored at
the memory positions of the memory corresponding to the tone production
timings in the rhythm pattern of the chord notes. Stored signal "1" is
read out according to an address signal from address generator 24, and
then is shaped into a short pulse so as to produce the beating pulse PC.
These beating pulses PC are applied to the tone generator 15, and only
while the pulses PC exist the chord tones are caused to be produced so
that a rhythm is given to the chord tones.
In accordance with the chord progression pattern which is selected by the
tonality designation switch 21 and the chord progression designation
switch 20, the chord tones are sounded from the sound system 3 in response
to the rhythm pattern of the beating pulses PC in every measure. The bass
tones are similarly produced from the sound system 3 one after another in
accordance with the rhythm pattern of the key-on pulses KONP.
FIG. 6 shows another example of the chord note data producing circuit 12.
In the example in FIG. 3, the note name data of the subordinate notes is
produced by adding the tonality data to the degree data of the root note
in a scale (chord degree data) so as to produce the note name data of the
root note, and then adding this note name data of the root note to
numerical values depending on types of the chord to provide the note name
data of the chord constituent notes. However, in the example of FIG. 6,
three note degree data indicating the degrees of the root note and the
subordinate notes of the chord are respectively produced as chord degree
data, and thereafter the note name data for the root note and the
subordinate notes are produced independently by adding the tonality data
(C, C.music-sharp., etc.) to the respective ones of these note data. In
FIG. 6, there are the same common parts as that in FIG. 3 to which the
same numbers are assigned (decoders 37-39, OR circuit group 40, etc.).
In FIG. 6, a chord progression pattern producing circuit 65 produces
various chord progression patterns (for example,
I.fwdarw.VIm.fwdarw.IIm.fwdarw.V.sub.7 etc.) in the same way as the chord
progression pattern producing circuit 30 in FIG. 3. The progression
pattern is selected by the chord progression designation switch 20 and
each of the chord degree data (I, VIm etc.) constituting the selected
progression pattern is read out in every measure, in accordance with the
measure number data Dc from the measure counter 22. However, the manner of
reading out the chord degree data is different from that in the example of
FIG. 3. In other words, in the FIG. 3 example, the chord degree data (for
example, VI) and chord type data (for example, m) were read out. However,
in the example of FIG. 6, the chord degree data is read out in a broken up
form as three note degree data identifying the root note and two
subordinate notes of the chord. For example, where the chord degree data
is Im, the three degree data of the notes I, II.music-sharp. and V
constituting this chord are read out. Exemplary manners of directly
producing these degree data are as described below.
First, the chord degree data (for example, Im) is divided into root note
degree data (I) and chord type data (m) as in FIG. 3. The degree data (I)
of the root note is outputted directly, but the note degree data
(II.music-sharp. and V in the case where the type of the chord is m) of
the two subordinate notes are produced by adding numerical values (+3 and
+7 in the case where the type of the chord is m) to the note degree data
(I) of the root note within the chord progression pattern producing
circuit. As another manner, the note degree data of the root note and the
subordinate notes of the chord are all stored in advance corresponding to
the chord degree to be played so that they have merely to be read out for
direct use.
As in the above, the three note degree data of the root note and the
subordinate notes produced from the chord progression pattern producing
circuit 65 are respectively applied to adders 66-68, where the tonality
data from the tonality designation switch 21 is added to these three note
degree data so as to change them to the note names. For example, assuming
that the chord degree data selected by the chord progression pattern
producing circuit 65 is Im, the three degree data outputted from the
circuit 65 are I ("0000"), II.music-sharp. ("0011") and V ("0111"). Also
assuming that at this time the tonality designated by the tonality
designation switch 21 is D (tonality data "0010"), the sum of the tonalit | | |
