Sometimes I don’t think far ahead of the possibilities in Live. I’ve been used to chop audio loops into tiny parts, and sprinkle them here and there, or take four-bar loops and chop them into smaller parts, and rearrange the entries in the arrange view, so that the song has a variation instead of this same boring four-bar loop playing over and over again.
Well, one could do the same thing with MIDI loops in Ableton Live’s arrange view! This makes it possible to make really interesting and variated MIDI sequences inside Live. Just chop and possibly set the loop point for the MIDI clips, as well, as you could loop the MIDI clips in Ableton Live as well.
Another option is to chop a MIDI part, and then go in and select all the notes and push them up an octave, five notes, or so. Or, you could just copy the MIDI track or part of it, and drag it into another MIDI track and another synthesizer. Or, this other track has an arpeggiator Ableton live plugin, or any other of the fun MIDI plugins provided by Ableton.
Then there’s the old trick of taking the bass line, copying it over to another MIDI track, and add another bass line to emphasize it, either with an octave higher synth, or some other sound. Or, you could do it multiple times, hey, now we are into the fat electro house domain!
Anyway, think of the MIDI clips as another way to take such “lego pieces” and arrange them in new configurations.