Quantity   Component name
1 × Host computer This might work on a Pi eventually, but not right now. Needs enough USB/COM ports for all your devices
1 × Fubarino SD / Arduino compatible board Main controller (could be any MCU with Serial, really). You'll need more if you have a LOT of floppies.
1 × 3D printer/ CNC machine More than one is supported. Optional (heck, everything here is optional, as long as you have at least 1 instrument)
8 × Floppy drives Any number from 0 to.. Well, however many you have
2 × old hard drives/ noizy solenoid devices Again, any number, as long as you have enough pins on your MCU(s)
2 × PNP Transistors To power percussion. Also some resistors (2 per transistor)
1 × Old ATX PSU Any beefy 5V power supply will do, needed to power floppy drives. If you only have 1 or 2, USB power is sufficient.
2 × Sandbar resistors Wired to 5V and 12V rails of ATX PSU to keep it from dying of undercurrent. Values depend on PSU, some might not need it at all
4 × Floppies Putting some floppies in the floppy drives alters the sound they make. Optional
50 × female-female header ribbon cable To wire floppies to MCU and PSU. 5 per drive (5V, GND, step, direction, enable), 2 per percussion and some more for misc. stuff