Entry Number Five
From "The Band Episode" (02/27/1998) of television series Sabrina the Teenage Witch.
Sabrina uses her magic to make a talent potion she and her friends (Harvey and Valerie) drink so their band will be good enough to play the school talent show. They forget to pick a name, so they are introduced as "entry number five."
There's a guest cameo by the Backstreet Boys.