Show tooltips for central buttons?

[misuba]

A couple of us have had the experience of coming back to Vutu after a little time away, mistaking the resynth-export button for the partials-export button, and being momentarily confused as to why it was trying to save a WAV file. Now that I type this all out, I honestly wonder why the two have the exact same name, but still: one possible balm for this and other confusions would be using the space above the central button bank (this is just one idea) for some short tooltip text.

[madronalabs]

I'm trying to design with tablets in mind, so don't think tooltips are the answer but there should definitely be onscreen help of some kind, at some point.