In The Simpsons season 33 finale, featuring The Simpsons musical, the series finally explained one of its oldest unanswered mysteries. The Simpsons takes place in a heightened version of reality, something that can work in the show’s favor and to its detriment depending on the episode. Sometimes, the fact that The Simpsons doesn’t align with reality allows the show to tell wild, goofy stories that would never work in a live-action sitcom. This can include the occasional The Simpsons musical moment.

Music has always been a big part of the show, whether it be The Simpsons' iconic Planet of the Apes musical or appearances from well-known musicians. However, there have also been plenty of times the show has veered into a full-blown musical with elaborate numbers that the characters seem to have prepared. Such brilliant musical moments on The Simpsons include "The Monorail Song," Mr. Burns' "See My Vest," and cult "Stonecutter's Song." However, one question surrounding The Simpsons' musical moments was finally addressed.

The Simpsons Season 33 Musical

Bart Simpson wearing a tie

The Simpsons season 33 finale, “Poorhouse Rock,” provided an answer to The Simpsons musical question. When Bart’s treehouse went up in flames at the end of an elaborate musical number, he yelled, “wait, so this was all real?!” offering an answer to the tricky question of whether or not musical numbers take place in the reality of The Simpsons or inside the character’s heads. Particularly on a cartoonish, surreal show, this question is a tough one.

On one hand, characters like Bart and Homer aren’t usually smart enough to improvise lyrics off the top of their heads, but on the other, much more absurd and larger-than-life things happen within the show’s goofy heightened reality every week. This moment, however, proved that musical numbers can occur within the universe of The Simpsons, but Bart’s shock simultaneously implied that this is an exception rather than the rule.

Are The Simpsons Musicals Real?

Hugh Jackman and Bart in The Simpsons Season 33 Finale

Bart’s terror at being trapped in a burning treehouse meant that the character had, until that point, assumed his entire lengthy musical number, which included cameos from Robert Reich and Hugh Jackman, was all some sort of elaborate fantasy sequence. In most musicals, this is how songs are treated, with only a few of the genre’s classics (such as Cabaret) featuring explicitly diegetic songs. However, because The Simpsons depicts mutated fish, chili-induced vision trips, alien visitations, and all manner of scenes more surreal than the former Secretary for Labor singing about the declining middle class to Bart, it can be tough to tell what is and isn’t "real" on the show.

As a result, Bart’s exclamation finally clarified something that viewers of The Simpsons could never have been entirely sure of before the season 33 finale. Most of the musical numbers on The Simpsons (judging by Bart’s shock, at least) are intended to be non-diegetic. Occasionally, they can be rooted in the reality of the series, but if Bart’s reaction to his terrifying predicament is to be taken at face value, most of the songs sung on The Simpsons take place in the heads of the characters doing the singing.