"Sit Down, You're Rockin' The Boat" from Frank Loesser and Abe Burrows' GUYS & DOLLS is the kind of show-stopping number that audiences eagerly await.  Often occuring towards the end of the second act, these numbers are commonly referred to as "11 o'clock numbers," since, in a lengthy Broadway show, such numbers would be performed at around 11 pm.  11 o'clock numbers are traditionally moments of revelation for the main character, where everything they've been struggling with throughout the show becomes clear.

The classic example of an 11 o'clock number is "Rose's Turn" from the Sondheim/Laurents/Styne musical GYPSY.  Rose, after spending the entire show pushing her daughters towards stardom at all costs, finally realizes that she's been trying to live vicariously through them.  Since she couldn't be a star, she could at least create one.



"Gimme Gimme" from Jeanine Tesori and Dick Scanlon's THOROUGHLY MODERN MILLIE is a more modern example: Millie, discovering that love is more important to her than money, gives in to her love for Jimmy, abandoning her dream of marrying her boss.  Both songs, while sung by entirely different characters in very different situations, serve the same purpose in the show, since they appear at similiar moments in the characters' storyline.

What makes "Sit Down, You're Rockin' The Boat" unusual in that none of the four leads sing the song.  Instead, the number goes to Nicely Nicely, a minor character, and seems to have nothing to do with any of the leads' arcs.  The song takes place during the meeting in the Mission Sky has arranged, after winning the gamblers souls in a bet.  When confronted by a suspicious police officer, the gamblers are forced to publically testify.  Nicely Nicely's testimony takes the form of an exposive ensemble number, "Sit Down, You're Rockin' The Boat."  The song certainly plays a role in terms of plot, as it helps convince the police officer that the gamblers are there for a genuine Mission meeting, which in terms helps Sky save the Mission.  But it's not the moment of revelation for a principle character an 11 o'clock number generally is.

Or is it?  Nicely Nicely easily could have spoken his testimony, rather than sung it.  The following number, "Marry The Man Today," could have been replaced by a bolder, more musically crowd-pleasing number that expressing Sarah and Adelaide's resolution to change Sky and Nathan after marriage.  But the quiet, matter of fact nature of "Marry The Man Today" doesn't exactly make it 11 o'clock number material, especially since "Sit Down, You're Rockin' The Boat" unquestionably fits the musical model of one.  Perhaps "Sit Down, You're Rockin' The Boat" is more than an excuse for a rousing ensemble number late in the show.

The answer is in the lyrics.  On the surface, Nicely Nicely doesn't seem to be speaking of anything other than a fictional dream, concocted to convince the police officer of the gamblers' pure motives.  Nicely Nicely sings of the necessity of going with the flow without drawing attention to oneself, "or the Devil may pull you under."  This advice is not unlike the course of action Sarah and Adelaide agree on in "Marry The Man Today."  No longer trying to fight Sky and Nathan's undesirable habits, the women agree to leave them be until marriage.  In other words, they've decided to stop "rockin' the boat."  This is also true of Sky and Nathan.  At the moment of the song, Sky is trying to save Sarah's Mission, even though she's made it clear she has no use for a scoundrel such as him; he's hoping to convince her of his reformed ways.  Nathan has similiarly relented to Adelaide's wishes, setting a date for the wedding and intending to actually go through with it.  Like their girlfriends, both men have decided to "sit down" to avoid "rockin' the boat."

With two pairs of couples each with their own storylines, coming up with an 11 o'clock number for each character to sing would not have been practical, and finding one song for the four to sing easily could have been cumbersome that late in the show.  "Sit Down, You're Rockin' The Boat" solves the problem of expressing a revelation shared by four characters, while providing the audience with a fun, upbeat ensemble number that has the momentum to carry the audience through the rest of the show.