Here's one nobody was expecting: Metallica and Lou Reed have gotten together and recorded an entire collaborative full-length album, Metallica announced on their website yesterday. The LP doesn't have a title or a release date yet, but they finished recording it last week, and it's 10 songs long.According to the Metallica website, the idea for the album came after the band performed with Reed at the Rock and Roll Hall of Fame's 25th Anniversary Concert, which went down at Madison Square Garden in 2009. Eventually, Reed came to Metallica's San Francisco home studio to record. Late-period Metallica are notorious for spending years on albums, but they bashed this one out over a few months.

Below, check out video of Reed and Metallica performing a crunching, solo-heavy rendition of the Velvet Underground's "Sweet Jane" together at the Rock and Roll Hall of Fame 25th Anniversary Concert.