Sonic Pi is used to play a piece written for the Oud, using 5 samples to generate all the notes. The Oud is an instrument a bit like a lute, used in North Africa and Middle Eastern Countries. A voice commentary is added to explain what is happening. The same piece is developed to be played either by a synth ( :tri ), or by an Oud sample-based voice.
This is a technique I have used for other instruments, including grand-piano, xylophone, glass armonica, flute, harp and church bells!
Many of these are documented in my blog http://rbnrpi.wordpress.com