| 摘要 |
PURPOSE:To start automatic accompaniment always at required timings without being affected by the operation of foot keys by changing over foot key and automatic base accompaniment in sychronization with the pulse signal of a narrowed width at the leading edge of the attack signal or its vicinity. CONSTITUTION:When the attack signal ATD for assigning base/auto base changeover assignment is applied to an attack pulse generating circuit 44, pulses ATK- p of a narrowed width at the leading edge of the signal ATK or its vicinity are generated by FFs 44a, 44b, NAND gate 44d, etc. to which the timing signal is applied, whereby the automatic base accompaniment is accomplished. On the other hand, the SR tupe FF 43b of a foot key auto base changeover signal generating circuit 43 is reset by this signal ATK-p, whereby the accompaniment is changed over to the automatic accompaniment. Hence, even if the signal FOOT being applied to the circuit 43 disappears and the accompaniment has been changed over from the foot to automatic accompaniment, the FF 43b does not invert until it is reset by the signal STK-p. As a result, the automatic base tone accompaniment may be started always at a correct timing without being affected by the operation of the foot keyboard. |
