Silly Song

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.

Film

 * 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.

Western Animation

 * 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.)