There's many synthesizers that use a Teensy as the brains of the thing. My favourite by far is the Dirtywave M8, which is an incredible bit of hardware & softw

There's many synthesizers that use a Teensy as the brains of the thing. My favourite by far is the Dirtywave M8, which is an incredible bit of hardware & software design, in UI & UX. They're unfortunately sold out, now, but they're incredible bits of kit. If you have a Teensy and some spare time, check out the Headless version of the firmware: https://github.com/Dirtywave/M8HeadlessFirmware https://github.com/Dirtywave/M8HeadlessFirmware -- upload it to your Teensy, and head to https://m8.run https://m8.run to get a fully featured tracker in your browser. The Polyend Tracker is another portable synth that is backed by a Teensy -- not quite as neat, but still neat.