Strike Up the Band or Else

Oscar owes Billy Joe Babcock, who is throwing a square dance at a fancy hotel in town, $500, and coerces Felix to change his band's style of music (they are called "The Sophisticados" and change their name to "Felix 'Red River" Ungar and his Saddle Sores) and play the square dance, as the original band meant to play cancels out at the last minute. By doing so, Oscar's debt to Babcock will be wiped out.