To play with a sound other than a piano, change the waveform used. The timbre option on play lets you create an instrument sound from a few numbers. Experiment by changing the numbers in clapsound.
Adding Percussion
Which songs have you already played that could benefit from some clapping rhythm? How would you add these sounds to your songs?
Synthesizing Sounds using different waveforms
The 'noise' waveform is good for percussive sounds. To make a tonal sound, use the 'square', 'sawtooth', 'triangle', or 'sine' waves. Experiment with waveforms. Try creating a Piano with a custom timbre.