Great news for all Amstrad CPC musicians. BetaSoftCologne aka BSC has released the sources for his new tracker called "AYAY Kaeppttn". Now everybody can do SIDsound on the CPC!
As you can see, the interface is currently rather minimalistic. But well, it does the trick:
The sources are hosted at Github. Some technical backgrounds and pointers on how to use this software are discussed on CPCWiki.