Why do so many television shows have a musical episode?
Very astute observation, person who asked this question. This phenomenon is actually due to an important sub-clause in the very hush-hush mega-deal that all Hollywood studios reached with the RIAA (Recording Industry Association of America) in 1953. From that date forward, completely outside of royalty and licensing fees charged by the individual publishers and record labels, this secret deal has allowed the Hollywood movie and television studios to include music in their productions. This includes all music and expressions of musical intent, from ambient background music to blaring pop songs playing over the end credits, to characters listening to radios, and even to child actors banging pseudo-rhythmically on pans. The sub-clause in question requires that any long running television show, lasting at least six on-air seasons, is required to include one musical episode during its run, unless said show is of a serious dramatic nature, science fiction based, or involves frequent character deaths, unless said show also incorporates a considerable amount of music as a regular feature. Failure to comply with this agreement could result in the offending company being denied access to all music going forward.
Astute readers would be correct in assuming that this clause was also the driving factor that lead to the common practice of the television show opening theme song, and the inclusion of music in the end credits of movies. These are attempts to help the studios reach the RIAA music quota in the hopes of avoiding the necessity of having their actors attempt to inexpertly belt out a series of poorly constructed songs.
*Disclamer: “Facts” are not to be confused with actual facts. “Facts” are meant to sound at least vaguely plausible, but have undergone no actual research and any relation to real answers to questions is entirely accidental.