Apple’s (AAPL) GarageBand ($14.99) is a versatile, and cheap, recording program that lets you record song ideas and demo tapes on your Mac. Today I’m going to look at various USB options to plug your instrument into GarageBand. Fortunately, there are a lot of different devices out there that will let you perform this task. That said, I’m going to focus on a cross section of these input devices, not the entire spectrum. While I’m going to use guitars as a frequent reference point since that’s the instrument I play, any of these input devices should work on instruments that have a 1/4″ output.