Radio City Revels (1938)

Pleasantly lightweight and silly comedy about a dimwitted musical genius from Arkansas who can compose brilliant songs - but only while asleep, never remembering them upon waking. He moves to the big smoke and is exploited by a ruthless duo of producers. This involves some pretty funny scenes of them trying to get him to fall asleep (once asleep he starts singing, and they feverishly write down the music and lyrics, and publish them themselves) - though perhaps this gag is overdone a bit in the scene where the bedroom gets filled with pigs and ducks and sheep.

Watch out for Ann Miller in an early scene, doing some dance steps which ought to be physically impossible.

No classic, but well worth a watch.