I have a very old tin-record music box. The motor is missing (used to be a wind-up spring motor). I'm thinking I might be able to use an electric motor of some sort(plugging it into the wall socket) and maybe some sort of controller mechanism to slow the thing down. The old tin record needs to spin at no more than 2 or perhaps 3 RPM. I realize I can cheaply purchase a DC electric motor, but I have no idea how to slow down the RPMs to a crawl without the thing burning out. Any ideas? Does some company sell very slow adjustable RPM electric motors? I don't need anything powerful, it must plug into the house sockets, and it needs to be only 3 or 4" in height max in order to fit into the old box, and it will need some sort of protruding 1/4" thick or less spinning rod so I can attach the small mechanism on which the tin record rests. Thanks for any ideas.

You needs something with a gear reduction system in it... and if you use a DC motor you can play with things like voltage to get it dialed in right. But no direct drive motor can do that.

Here is a 2 RPM Motor:
Here's one for about $25:
http://www.servocity.com/html/2_rpm_gear_motor1.html

Here is an expensive one:
Amazon.com: Dayton AC Parallel Shaft PSC Gear Motor 2 RPM, 1/20hp 115 Volts 60HZ. (3M125 ) #1LPN8: Home Improvement (http://www.amazon.com/Dayton-Parallel-Shaft-Motor-Volts/dp/B000BH1MMC)