DREAM produces a comprehensive range of DSPs that vary in power and functionality, making them suitable for keyboards, electric pianos, drums and many other instruments. To aid design, DREAM offers numerous licensable code banks, some of which are free, as well as tools to create and edit your own samples. There is also a wide range of development kits and evaluation boards available.
The DREAM DSPs are packed full of useful peripherals and come with on-chip RAM. Use the APS1604M if you require extra memory for long delays or processing.
The USB charger NJW4119 is another IC to consider.