So your aging hard drive can't hold its data any longer and you replaced it with a new one. Instead of letting it die by the hands of the recycling undertaker, you force it into a new life as a musical noise maker. A dying hard drive makes all kinds of grunts and groans as it starts up. The sounds it makes can be musical and percussive.
This project uses a homemade PIC midi interface to allow sequencer software (Anvil Studio free) to turn on and off eight hard drives. Midi signals are serially transmitted by the sequencer software as sets of 3 bytes at 31,250 baud. A PIC 16F877 has been programmed to receive these bytes to turn on and off solid state relays. Each hard drive needs 5 volts and 12 volts to run. Two SSRs are used to turn on and off the hard drive. I tried leaving on just the 12 volts, then switch on 5v to start the drive up. This worked well for awhile until one smoked up. So I use two SSRs to switch on both 5 volts and 12 volts at the same time. A modified PC power supply is used to supply power. A guitar tuner pickup and computer soundcard amplifies the sounds, making the point that something went horribly wrong with those drives.
You probably upgraded you computer in the past with a larger power supply and its just sitting in your garage getting dusty. You can use that power supply (if its still working) to power this project. Start by locating the +5/+12 connectors that would normally connect to the hard drive. Cut off the connectors and run the wires to a terminal block to make wiring easier. You can get some new connectors at a place like Fry's Electronics to wire up the drives. Black is common (the negative connection), red is +5 and yellow is +12. Below I added a second set of connectors (toward the left) so I can detach the power supply from the project. You will also need a minimum load through the power supply to get it to turn on. I used a 30 ohm/20w and 50 ohm/20w power resistors across the 12 volt output and a 10 ohm/10w across the 5 volt output. A 12v and 6v auto tail light bulb will also work as a load