I wanted to try hooking my guitar to my Mac, so I looked up cables. I thought I’d need some kind of fancy cable that would translate electric guitar into bits, but no: it turns out you just need a 6.25mm cable plug one end with a 3.5mm plug on the other. I plug it into the microphone jack.
Once I had my guitar plugged in, I fired up Garageband, and I could play through my computer, which was pretty neat. I’ve been working on some music with two parts, so I tried dueting myself. The first attempt sounded pretty terrible, but then I realized that I could re-record each part against the other, improving each one as I went along. Eventually, it sounded . . . slightly less terrible. At any rate, it’s an interesting proof of concept. I have some friends who know a lot more about this sort of thing than I do, so I’ll have to pick their brains a bit.