Hey all,
This new FM synthesiser shield on kickstarter is really close to its goal with like 4 hours left to go.
Check out the examples of custom instruments and all the tutorials. The Arduino library looks great.
https://www.kickstarter.com/projects/1304489933/opa-multitimbral-fm-synthesizer-shield-for-arduino
Sounds great and also good for chiptune stuff.
Cheers!