Homer formed a barbershop quarter known as The Be Sharps with which other three characters?
Homer Simpson formed a barbershop quartet called The Be Sharps. The group consisted of four characters from "The Simpsons":
Homer Simpson (as the lead singer) - He initially formed the group and was the primary driving force behind its success.
Seymour Skinner (as the tenor) - Skinner was the principal of Springfield Elementary School at the time and joined The Be Sharps.
Apu Nahasapeemapetilon (as the baritone) - Apu, the owner of the Kwik-E-Mart, also became a member of the quartet.
Chief Wiggum's father (as the bass) - Chief Wiggum's father, who was portrayed as being quite elderly, completed the quartet as the bass singer.