FOLLOW UP: We released some updates summer 2017 in an attempt to rewrite the Macchiato to compile on a more recent version of Arduino and Mozzi. These updates had some stability and other performance issues, and we recently reverted to a vamped-up version of the old code. So the latest release, v1.1.2 (software file v1_171024) is packed with the latest features, sounds a little better and is every bit as stable as the original Macchiato — but it still has to be compiled with Arduino 1.0.5r2.