When Booth is disappointed when seeing the Rock and Roll Seminar line, he comments "Does anybody remember laughter?". This is a line Robert Plant (lead singer of Led Zeppelin) used to add to the live version performances of "Stairway to Heaven".
It is established that Booth views Led Zeppelin as one of the greatest rock'n'roll bands ever. Led Zeppelin is also heavily referenced throughout the episode.
The victim's name is Richard Cole which is a reference to Led Zeppelin's tour manager of the same name. Richard Cole was not only their tour manager, but also wrote the unauthorized biography Stairway to Heaven: Led Zeppelin Uncensored.