My brother posted a video about this on facebook almost a year ago. Some old floppy drives playing Bach's masterpiece Toccata & Fugue and it got me really interested. So I read about it when the author posted a how-to on his blog and did a couple of tweaking using SammyIAm's Musical Floppy program when the project gained a lot of attention.
WHAT YOU NEED
1) Arduino - Ideally, you need the Arduino UNO but any Arduino would work. You just need to tweak something in the program with the pin assignments. In this mini-project however, I used Duemilanove. It works almost accurately as Arduino UNO and I didn't have to tweak anything.
2) Floppy Drives/Disks - Any floppy drive would work but it's a lot easier to use the 34-pin simply because it's common. Other than that, you would only be needing to determine 3 pins from your floppy. Pin assignments are available online, particularly here. Furthermore, I was trying to acquire a 5.25 floppy drive but to no avail, and ebay sells them around $20 so I said never mind about that. As a result, this project is composed only of the 3.25 floppy disk drives. You also need some floppy diskettes for this project.
3) Power Supply - Again, it depends on you. You can use any 5-volt power supply available but since an ATX power supply is just lying around at home, I conveniently used it instead.
4) CAT5 UTP Cable - Only because of the wires. I want my wires to be color-coded.
5) Breadboard - If you want a solderless-free project.
6) Soldering Iron/Lead - For soldering the pins you would need to connect your CAT5 UTP cable to, but if you still have the flat ribbon cable then good for you. Might as well use that to make it easier.
7) Cutter, Phillips/Flathead screwdrivers - For dismantling purposes.