I had a scour through some tracks I had written today to try and find something that would be suitable for the interface prototype. Using Ableton Live, I selected a few tracks and rendered them off as .aiff loops. I had to make sure all my volumes and effect levels were all correct here as Keynote will play all audio files at the same (master) volume.
After experimentation in Keynote, I also realised that you cannot synchronise 2 loops on the same screen – for example, when I placed a bassline loop and a lead melody loop on the screen, they eventually would go out of sync – even though they were recorded at exactly the same tempo. Because of this, I then went back into Ableton Live and rendered the loops off as “builds” – so the loops became assembled like so :
Drone + Arpeggio.aiff
Drone + Arpeggio + Bassline.aiff
Drone + Argeggio + Bassline + Lead.aiff
This way, only one loop was placed on any Keynote screen, but comes across to the user as a building of loops, (when dragging objects onto the stage) but it isn’t. Nothing goes out of sync now, as it is just one audio loop on every screen.