Do you know I have never tried it! Altering the sound etc., whilst it is playing!
You've given me something to try out now?
But you can certainly play about with the tune if you have a suitable software programme on the computer. Changing the voice, tempo, and beat, etc. Adding other instruments and things like that.
The Yamaha PSR540, really does have a true sound. The default voice is a Grand Piano and that, like every other voice on the instrument is remarkably close to the real thing.
Bye for now.