What occurs when characters who are normally at least somewhat straight-laced decide to shake things up and get down with their bad selves to, well, a Silly Song. The characters don't even have to be singing the song themselves. Someone unseen or offscreen could be singing it, or it could obviously be playing on a radio or stereo or over a P.A. Whatever the case, the characters will (sometimes literally) drop whatever they're doing and break into a boisterous (and, uh, totally spontaneous) dance sequence (or maybe some rollicking slapstick or acrobatics) that never fails to get the audience right into the mood along with them. When the song is over, the characters will almost always simply resume their previous activities as if they'd never stopped performing them. Pretty much obligatory in any musical (and not just in the Western world, either). If the entire show is silly, this is the number that is by far the silliest.
- In The Gay Divorcee (1934), the guests at the seaside hotel, including fussy lawyer Egbert Fitzgerald, do a random silly dance and song called "Let's K-nock K-nees."
- Definitely the "Surfing Bird" sequence in Back To The Beach. It is relevant to the plot (such as it is), but also features dancers wearing outrageous wigs and an unexpected solo by Pee-Wee Herman, who arrives without warning and then leaves just as quickly.
- "Blunt the Knives" in The Hobbit: An Unexpected Journey. When Bilbo complains about the dwarves' table manners, they burst into a song where they mock him. The film is otherwise not a musical, and features only one, much more serious song (not counting a few lines sung by Gollum and the Great Goblin). The scene and the song was also in the book, but it features much more songs and poems, so this particular one stands out a lot less.
- The Muppets features Tex Richman's impromptu rap, doubling as a Big Lipped Alligator Moment and a Villain Song. Keep in mind that Tex Richman is, for the remainder of the movie, a very serious and brooding character. The ridiculousness of what just happened is quickly lampshaded.
Tex: The answer is no.Kermit: You could've just said that.
- In the film version of Sweeney Todd: The Demon Barber of Fleet Street, "By the Sea" is this, mainly due to the bright and beautiful imagery, which dramatically clashes with the rest of the film's grime and darkness, and the fact that it's a cannibal singing about how she'd like to settle down and live by the beach. The hilarity is compounded by Sweeney thoroughly not getting into the musical number.
- So, so many Disney classics:
- Snow White and the Seven Dwarfs: "The Silly Song" (appropriately enough)
- Pinocchio: "I've Got No Strings"
- Dumbo: "When I See An Elephant Fly"
- The Little Mermaid: "Les Poissons" (definitely counts as a BLAM song)
- Beauty and the Beast: "Gaston" (also counts as a Villain Song)
- Aladdin: "Friend Like Me"
- The Lion King: "Hakuna Matata"
- Pocahontas: "Mine, Mine, Mine" (again, also a Villain Song)
- The Hunchback of Notre Dame: "Topsy Turvy." (Also maybe "A Guy Like You," although in context that's more of an "I Am Becoming" Song.)
- Frozen: "In Summer", which is played for lots and lots of Black Comedy.
- "And now it's time for Silly Songs with Larry, the part of the show where Larry comes out and sings a silly song."