NeoTrellis M4

The NeoTrellis M4 from Adafruit is a developer board for building your own digital musical instrument. It can be used as a USB midi device on a PC, mobile or tablet, or as a standalone musical instrument programmed with almost any sound you like. You can also use a mobile phone headset with mic to create your own unique digital sounds. It also has a built in accelerometer to create sounds using tilt and motion. It can also be programmed to do more than create music, such as make a game or a controller for other devices, you are limited only by your imagination.

There's a 4x8 grid of elastomer button pads with a NeoPixel nestled in the centre of each one. You can read any/all button presses simultaneously thanks to the fully diode'd matrix, and also set each button color to any of 24-bit colors. The elastomer buttons are translucent so they glow beautifully when lit.
Source - Adafruit