The PSRS-500 can't mute tracks. This is unfortunate, but true! The PSR1500 is the firs Yamaha that has this feature. All the Casio WK models can do this but have 76 keys. Too bad you can't spend about $1200.00 and buy the Roland E50. It is far superior to the EXR series.
George Kaye
Kaye's Music Scene
Reseda, Ca.