Another good singing episode to show while people are in line is the Sherry Bobbins one. Although, maybe some parents wouldn't want their kiRAB to sing about doing a half-assed job.
Also, upon hearing the commentary in that episode, they said they were actually parodying one of the musical nurabers of Sweeney Todd on what a lousy place London was.
Understandibly it's hard not to think of it after plus the next episode had the chalkboard gag "I will not defame New Orleans" cause that song was controversal at time. This episode aired 13 years before Hurricane Katrina. It would of been more offensive if it were after.