Billie Joe Armstrong was at the Tribeca Film Festival in New York City on Saturday night (April 23) for the premiere of the film Geezer, which sees the Green Day frontman star as an aging punk rocker struggling to acclimate to a subdued family lifestyle. 

Armstrong also brought his band in tow—albeit without bassist Mike Dirnt—for a surprise performance, and teamed up with the legendary Joan Jett in the process. Watch fan-shot video of the supergroup playing "American Idiot" and Jett's classic song, "Bad Reputation" above, which—apologies—is a little bouncy and rough at times.

If that footage was a little nauseating, check out the more settled video below. Jett comes in at the 4 minute mark:

In other Green Day news, the band recently revealed that they're working on new music: A video Armstrong posted to Instagram earlier this month showed drummer Tré Cool fooling around and laying down a new track behind the drum kit. The band's last full-length record, 21st Century Breakdown, was released in 2009.