This is a Redstone device that can be used to play sounds with. Since noteblock music makers have to make their own noteblock sequence every time they wanted to create music, now this will help. With this device, you can just input the sequence of notes as a 4-bit data using levers (Documentation and full specs in-game).

But be warned that the sound system right now can only play one note per second, and can only store 12 notes (storage can be expandable). If you want to use to play music, try to expand the storage (There are 4 wires of Redstone at the side of the 6 bytes of storage where you can use to expand), and when recording, edit the video to be in fast motion.

Anyways, Have Fun! :)