Give me five minutes. I don't use GarageBand regularly. I'll see what I can do.
Blast. Just remembered I didn't actually install GarageBand on my Mac when I did my system re-install a few weeks ago. I'll see if I can find a tutorial.
Try that out. Page 38 and onwards might be of some use. Page 44 as well as 45. Give it a go. I'm not sure if that's up to date but it's the best I can find.