"Undone – The Sweater Song" is a song by the American alternative rock band Weezer, released on the band's self-titled 1994 debut album. It was released as their debut single in 1994. Weezer frontman Rivers Cuomo has commented on the song, saying: Cuomo has also said that it was his attempt at writing "a Velvet Underground-type song," but later referred to the song as an inadvertent rip-off of Metallica's "Welcome Home (Sanitarium)", with the band's metal roots showing through.