This is a programmable synthesizer in an Arduino-friendly shield form factor. It can also be easily used as a breakout board for use with other microcontrollers.
The Fluxamasynth is based on Atmel's ATSAM2195 single-chip MIDI sound system, which is part of their Dream Sound Synthesis line of programmable ICs. It was intended for battery powered keyboards or portable Karaoke machines, but I'm sure you can use and abuse the Fluxamasynth in all sorts of new and interesting ways. Here are a few suggestions:
The Fluxamasynth has a built-in wavetable with 128 general MIDI sounds and an additional set of 128 variations and dozens of percussion sounds. It can play music in 64-voice polyphony without effects or 38 voices with effects.
Here are some additional features:
The ATSAM2195 chip that does all the work is hooked up to the serial transmit (TX) line of the microcontroller; making music is as easy as sending a set of MIDI-formatted bytes to the serial port. If you need to use the serial port for something else, a jumper allows you to switch to pin 4 and a software serial solution instead of the UART.
You can program the Fluxamasynth with the Arduino IDE and the Modern Device Fluxamasynth library. See the Quick Start guide for a complete example.
This version of the Fluxamasynth comes fully assembled. You'll need an Arduino, Freeduino, BASIC STAMP or some other microcontroller to use with this shield. Modern Device will soon have a shield-friendly variation of the RBBB board that works great with the Fluxamasynth, or use the Wicked Device RBBB shield and an RBBB.
Other resources: