Movie poster from 1966

This movie had Norm Grabowski, Jamie Farr, and Bob Eubanks as recognizeable stars.
The movie synopsis: Teenage/secret agent/musical comedy about Big Daddy who's been "driven mad by rock 'n' roll," so he plans to sabotage a music fair with a bomb. Secret agent Homer comes to the rescue aided by his girlfriend Sandra along with Marvin. The sinister villains belong to the crime syndicate F.L.U.S.H.