There are provided a musical tone-generating apparatus which neither requires hardware having an increased circuit size nor imposes a heavy burden on a CPU thereof, and a mobile terminal apparatus including the musical tone-generating apparatus, as well as a musical tone-generating method, and a storage medium storing a program for executing the method. A CPU converts music contents data stored in a RAM to hardware tone generator control data, stores the resulting data into the RAM. In reproduction, the CPU reads out and sends the hardware tone generator control data to a hardware tone generator. A data decoder circuit of the hardware tone generator sequentially reads out the hardware tone generator control data from a FIFO and separates the read data into time management information and data of a parameter for generation of a musical tone, and sets the time management information to a counter. Under the control of the counter performing the time management, a register write controller writes data of the parameter into a tone generator control register at timing indicated by the time management information. A tone generator section produces the musical tone based on the data stored in the tone generator control register.