Fred forms a barbershop quartet to compete on the "Hum Along With Herman" television show, and in the process discovers that Barney is a natural lead tenor. The catch is that Barney can sing only when he's in the bathtub.
| Name | Type | Role | |
|---|---|---|---|
| Barry E. Blitzer | Writer | ||
| Don Messick | Guest Star | ||
| Alan Reed | Guest Star | ||
| Jean Vander Pyl | Guest Star | ||
| Mel Blanc | Guest Star | ||
| Howard Morris | Guest Star | ||
| John Stephenson | Guest Star | ||
| William Hanna | Director | ||
| Joseph Barbera | Director |