Abstract: A musical tone synthesizing apparatus, which has a musical tone memory, generates a musical tone by accessing the musical tone memory. In ordinary state, the tone generator directly accesses the memory and generates musical tones based upon the accessed data. On the contrary, when a microprocessor directly accesses, first, an initial address to be access in the memory is set. Then, musical tone data are consecutively read out from or written in the memory by automatic increment of the address which is started from the initial set address. As a result, it is not necessary for the microprocessor to designate every address of the musical tone data to be read out or written. So, the microprocessor is not overloaded.