Will Forte guest starred as King Toot, and musician Sammy Hagar appeared as himself.
Homer gathers Reverend Lovejoy on guitars, Kirk Van Houten on keyboards, and Dr. Hibbert on drums.
Apu later joins as the lead singer when they hear him sing "Hopin' for a Dream", a song by the (fictitious) 1980s glam metal band, Sungazer.
The gig is ultimately successful, the band gains recognition and Sungazer sees the video and asks Apu to replace their dead lead singer.
Without their lead vocalist, Covercraft's rehearsal sessions grind to a halt when Kirk volunteers to replace Apu and Homer criticizes his vocal abilities.
Marge reminds Homer that he did not start the band to become rich and famous, and encourages him to go to Sungazer's concert in Springfield Costington's arena to show his support for Apu.
In June 2014, writer and executive producer Matt Selman announced that Will Forte was cast as King Toot, whose business is next door to Moe's Tavern.
He highlighted the jokes but felt it was a missed opportunity to reference previous episodes where the characters were musicians.