I'm new to Ableton, so forgive me if I don't know what I'm talking about.

I'm trying to use Ableton Live 8 to to play short clips on my keyboards during performance while I'm playing guitar. The easiest way I've figured to do this is by playing MIDI clips in session view. (I use DAW Remote on my iPhone to navigate them.) And, so I won't have to go over to my computer to open a new file at the beginning of every song, I'm putting all the clips for a single performance in one MIDI track. The only problem with this is different songs should be at different tempos, but every clip will only play at the main tempo for the project. Is there a way for Abelton to recognize MIDI tempo changes in clips? Or am
I going about this all wrong?

I don't know if it matters, but all of my MIDI clips were recorded before I had Ableton, on Cakewalk Home Studio.