I HAD my glasses on! Sheesh. I've done that before, more than once. I think it is a failing on the part of Apple in terms of the user interface. The track headers should be much more distinguishable. IMOI should have put my glasses on.
Taking a fresh look, your MIDI flute region is on an audio track.
Create a software instrument track, move the flute region on it, and try your library again.