scatter band n. a group of musical performers, without traditional marching band structure, that perform unorthodox skits and songs at university sporting events. Etymological Note: The term originates in the way such groups tend to enter for performances: as a disorganized mob, screaming and running about. (source: Double-Tongued Dictionary)
Further reading
In 1916, a small-town newspaper in Pennsylvania printed a fanciful item about a local gathering with a guest list that included, among others, Miss Ella Vader, Mr. Ray Zor, and other punny names. This is part of a complete episode. Transcript of...
Elizabeth from New Orleans, Louisiana, is pondering the way catchphrases such as Matthew McConaughey’s Alright, alright, alright catch on and get passed around. These vocal memes or prosodic memes get repeated and passed around in a way that...
The term “scramble band” is also used; it may be more commonly associated with the Ivy League bands (except for Cornell).