How long did you stick with it? It cycles through the same few channels at the very beginning and starts you on the same channel (food channel?) each time, but after that I think you're in control.

EDIT: OK, so I messed with this some more. It does appear to change channels on its own from time to time, so it doesn't seem possible to see whether they recorded the entire song for each channel. Also, it didn't start me on the food channel this time. Nevertheless, it's not the same each time you do it. I suspect that each channel only contains portions of the song and there are enforced channel changes as a result