^^ You can modulate temp in Garageband 11. I've done it. What you can't change is time signature.
Essentially, you're not changing the pace of the song, you're speeding up or slowing down certain sections.
Likewise, I have made the tempo continuity snap away accidentally (pretty often, actually), but I don't know how I did it and thus can't actually do it the way I want to.
Essentially, my problem is essentially making "right angle" modulations. Every place I've gone online to find out how either says "it's the same way as if you were altering real instruments" (which means nothing to me) or "look at the help file" (which says the previous).
I figured it out... sorta. In any case, I made the song I was putting together work. So don't worry about it.
edited 19th Mar '12 8:41:24 PM by KnownUnknown
"My final prayer: O my body, always make me a man who questions!" — Frantz Fanon