The Hardy Boys / Nancy Drew Mysteries (1977)

S1E9 The Mystery of the Flying Courier

Joe Hardy takes the stage for his first singing performance at a disco, where he and Frank soon find themselves tangled in a record piracy scandal. While at the club, Frank spots a girl he believes has been missing for years. After her arrest, the brothers dive into an investigation involving a shady disc jockey and a host of other dubious figures in the music scene.