The Yamaha S90 XS is a music synthesizer that combines the sounds of the Motif XS, a handcrafted S6 piano, with the ease of use of a stage piano. It has 88 keys, a balanced hammer action keyboard, and 142 MB of high-quality S6 piano sounds. The S90 XS also features:
Real-time controls for tweaking the sound while playing
Audio recording to USB memory
Extensive computer music features
Initial touch, aftertouch, pitch bend, and modulation