When Riley packs his saxophone after rehearsal, he leaves the instrument strap around his neck. On the next cut, when Riley and Cooper are given new assignments, Riley is now no longer wearing the strap.
When Cooper is accompanying Marge's dance on trumpet, at one point he is featured playing a melody. The sound heard is of a trumpet being used with a mute or a plunger, but Cooper is playing an open trumpet without a mute or a plunger.