This is an OK Fred Astaire movie. A couple of good dance sequences - one with Paulette Goddard, who is not impressive on the floor, and one where he's tap-dancing while conducting Artie Shaw's orchestra. The plot is dismal, Burgess Meredith as comic relief is faintly amusing at best, though in his defense the script gave him very little to work with.
Fans of swing will want to see "Second Chorus", though, for the musical sequences. In particular, a five-minute fantasia that Shaw and the band (plus a string section) play. This piece has been scored and has been recorded several times under the title of Artie Shaw's Clarinet Concerto; but no other clarinetist, popular or classical, has brought the same excitement to the piece that Shaw did. It's worth renting for that sequence alone.
It's a real shame that the director couldn't work out a sequence in which Astaire dances to Shaw's clarinet - playing, say, "Begin the Beguine", or "Frenesi", or "Traffic Jam", or any other his many other hits. A real shame indeed.