Play V6 is a brilliant little project that is a 6-part, 8-bit music player, made from an Arduino Uno, some capacitors and resistors.
The nature of Arduino allows it to read many sensors, and control many components simultaneously. It can be used in many musical projects, not generally as the sound creator (although it can-ish), but as a controller. Many excellent new interfaces and performances can be made when the project maker decides they want to build a custom controller.
The ‘Piano Stairs’ is a little project that plays a different note every time you step on a step, playing a musical scale as you ascend.
The Arduino itself isn’t really capable of playing music on its own, but add an Anniken Andee shield, and you’re good to go!
The Multi-Touch is a touch controller featuring an 8×8 grid of LED loveliness.
The RN-9090 is an extremely well-built MIDI step sequencer that outputs pure MIDI to control external synths.
The Guitarduino is an Arduino based guitar project that lets you trigger loops and effects while you shred.
Ever wanted to make floppy drives play the James Bond theme? This nutty hacker has created a mini orchestra with 13 floppy drives and a HDD
The Meganome is a DIY MIDI controller created by Patrick Flanagan featuring an array of LED arcade buttons, and continuous controllers.
Due to limitations of the Arduino, music is generally a no-go, However, APC have cunningly managed to get the Arduino to play audio.
The Toa Mata Band is a collection of Lego Bionicles that play various musical instruments. They play drums, synths, glockenspiels and more!