Description:
BACKGROUND OF THE INVENTION
1. Field of the Invention:
This invention relates to a chord selection apparatus for an electronic musical instrument such as an electronic organ in which typical chords commonly used (mainly, chords for rhythm) are performed by simple manipulation.
2. Description of Prior Art:
In the playing of electronic musical instruments such as the electronic organ, there is a musical performance technique which plays the lower key board or manual to play chords for rhythm and the upper key board or manual to play a melody to an accompaniment of the rhythm. This musical performance technique, however, required rapid manipulation of the keys in accordance with the various kinds of the chord patterns. Further, since there are eight kinds of popular chord patterns such as a major, a minor, or a seventh chord, in general use, it is quite difficult to memorize the 96 kinds of keying patterns which are composed of these eight kinds of chord patterns assigned to each one of all the 12 key tones (C, C♯, D, D♯ . . . .), and to perform these 96 kinds of keying patterns as occasions demand.
SUMMARY OF THE INVENTION
Therefore, it is a primary object of the present invention to provide a chord selection apparatus whereby chord performance as mentioned above can be effected by simple manipulation. By using the chord selection apparatus of the present invention, a performer is able to perform various kinds of chords at will only by doing two different manipulations which designate a key tone and a chord pattern of a desired chord, and thus even a beginner is capable of a musical performance ordinarily requiring considerable technique. Moreover, the present invention may be utilized for instruction and rapid progress in learning to play an electronic organ.
According to the present invention, the foregoing and other objects are attained by providing in an electronic organ a key selection switch and chord pattern selection switches. First and second ring-counters are associated respectively with the key selection switch and the chord selection switches. The ring-counters are driven by opposite phase outputs of a common clock. Depressing a key in the key selection switch causes the second ring counter to be reset with the result that the second ring-counter will be counting in synchronism but delayed with respect to the first ring-counter. The outputs of the first ring-counter successively enable registers to provide outputs which are connected to signal output gates corresponding to each tone scale. The outputs of the second ring-counter are connected to a plurality of chord matrices. The chord matrices are connected through the chord pattern selection switches to the inputs of the registers which provide an output upon the coincidence of signals from the first ring-counter and one of the chord selection matrices.
BRIEF DESCRIPTION OF THE DRAWINGS
The specific nature of the invention, as well as other objects, aspects, uses and advantages thereof, will clearly appear from the following description and from the accompanying drawings, in which:
FIG. 1 is a block and schematic diagram of the preferred embodiment of the chord selection apparatus according to the invention; and
FIG. 2 is a timing diagram useful in understanding the operation of the apparatus shown in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment of the present invention will be described with reference to the drawings. A first ring-counter 1 in FIG. 1 operates in response to clock pulses A (see FIG. 2) applied from a clock-pulse generator 2 to produce output pulses from 12 output terminals numbered from 0 to 11 in order. The 12 count outputs obtained in this manner are applied to 12 registers 3-0, 3-1, 3-2, . . . . , 3-11 respectively. Each register 3-0 through 3-11 is composed of a D-type flip-flop, which reads input information D only when a clock-pulse voltage rises, and holds that information as a Q output of the flip-flop until the next clock-pulse.
The Q outputs of registers 3-0 through 3-11 are applied, respectively, to 12 signal gates 4-0, 4-1, 4-2, . . . , 4-11. These Q outputs cause their corresponding signal gates 4-0 through 4-11 to open so as to permit signal inputs applied to the signal input terminals thereof to be connected to the output terminal.
Each count output terminal of the ring-counter 1 is connected with each contact of a key-tone selection switch 5. This key-tone selection switch 5, when any one of switches thereof is closed by a player, feeds the count output from the count output terminal of the ring-counter 1 corresponding with that switch to a reset input terminal of a second ring-counter 7 by way of a differentiator circuit 6.
The second ring-counter 7 operates in response to clock-pulses B (See FIG. 2) of opposite phase to the clock-pulses A applied to the first ring-counter 1. Ring-counter 7 generates count-pulse outputs at twelve output terminals numbered from 0 to 11 in order. When a signal from the key-tone selection switch 5 is applied to the reset input terminal of the second ring-counter 7, the ring-counter 7 is reset regardless of its current count output and starts to count again from number 0 at this time.
Consequently, assuming the sixth switch (corresponding to the key of F on the musical scale) of the key-tone selection switch 5 is closed, for example, the second ring-counter 7 counts in synchronism with the first ring-counter 1 but five numbers behind.
The count output terminals of the second ring-counter 7 are connected with chord matrices, 8-1, 8-2, . . . , 8-n. There are as many chord matrices as may be desired for the major, minor, seventh, and other chords. The chord matrices 8-1 through 8-n are diode matrix circuits, and the input terminals thereof are connected with positions of the musical scales constructing each chord pattern, namely with the count output terminals numbers 1, 5 and 8 as to a major chord for instance. Then, the selected output of one of the chord matrices 8-l through 8-n is applied to each input terminal D of all the registers 3-0 through 3-11 when the corresponding one of the chord pattern selection switches 9-1, 9-2, . . . , 9-n is closed.
It will be assumed that the sixth contact of the key-tone selection switch 5 and the chord pattern selection switch, 9-1 which corresponds with a major chord, for example, are closed respectively. Consequently, the second ring-counter 7 as mentioned above, counts 5 numbers delayed from the first ring-counter 1, and thus the outputs appearing at the count output terminals numbers 1, 5 and 8 are applied from the chord matrix 8-1 to each input terminal D of the registers 3-0 through 3-11 through the chord pattern selection switch 9-1. Since the timing of the second ring-counter 7 lags in time equivalent to five output terminals thereof later than that of the first ring-counter 1, the signal appearing the counter output of number 1 of the second ring-counter 7 is applied to the input terminals D of the registers 3-0 through 3-11 when the pulse output at terminal 5 of ring-counter 1 is applied to the T input terminal of the register 3-5. Therefore, only the register 3-5 sends out the signal to the output terminal Q and causes the gate 4-5 to open. The circuit operation as mentioned above is effected as to the counter outputs numbers 5 and 8 of the second ring-counter 7, and the fifth and the eighth registers, counting the register 3-5 as the first one, namely the registers 3-9 and 3-0 cause the signal gates 4-9 and 4-0 to be opened by the Q outputs thereof. As a result, the tone signals corresponding to the F, A and C in musical scale appear together at the common output terminal of the signal gates 4-0 through 4-11, and thus the F-major chord is played. FIG. 2 shows the timing relationship of the sequence in the example described above.
As shown in FIG. 2, the clock pulse generator 2 produces opposite phase clock pulses A and B. Ring-counter 1 counts or advances on the leading edge A output of clock pulse generator 2. For the sake of simplicity, it is assumed in FIG. 2 that the key of C tone selection switch is closed. Therefore, the 0 output from ring-counter 1 is connected by the key tone selection switch 5 to differentiator 6. Differentiator 6 produces a reset pulse on the leading edge of the 0 output pulse from ring-counter 1. This reset pulse resets ring-counter 7 which thereafter counts or advances in synchronism with the B output of clock pulse generator 2. For the case assumed, i.e., the key of C tone selection switch closed, the ring-counter 7 counts one clock pulse phase delayed from ring-counter 1. If chord pattern selection switch 9-1 is closed thereby selecting chord matrix 8-1, output counts 1, 5 and 8 from ring counter 7 will appear at each of the D inputs of register flip-flops 3-0 to 3-11. Thus, the corresponding flip-flops will be set in accordance with the coincidence of the outputs from ring counters 1 and 7.
By applying the present invention, chords of any key tone can be performed at will by only manipulating one switch of the key-tone selection switches 5 and a chord pattern selection switches 9-l through 9-n.
It will be apparent that the embodiment shown is only exemplary and that various modifications can be made in construction and arrangement within the scope of the invention as defined in the appended claim.