Though this is technically composed by a band, I very much would consider this piece much more artistic and designed than a musical composition. I think it blurs the line between the two even further because of course this is still meant to entertain.
The project is called “Marble Machine”, and is composed by Wintergatan.
Here’s the video:
You may argue that this instrument is not computational, but the design of the note timing, the construction of the machine’s parts, and the overall structure of the music is absolutely computationally based. It’s a real-world manifestation, but it was definitely created computationally. The design of the notes was then put through a CNC Mill to create the physical note timing.