The cast went back to the New Moon star Robert Pattinson’s hotel room for an off-the-cuff jam session with the band Sage & the Dills, who are friends with fellow New Moon co-star Nikki Reed. This is revealed in the upcoming corner-store tabloid OK Magazine, which comes out Thursday–

As Robert, who plays dreamy vampire Edward Cullen, strummed his guitar, on-screen sibling Jackson Rathbone (Jasper) played harmonica while their big-screen sister Nikki Reed (Rosalie) added lyrics she had practiced onstage earlier that evening while serenading cast mate Taylor Lautner.

“We just got really creative,” lead singer Sage tells OK! of the intimate hotel-room session, which sounded like a mix of old-school rock and country as well as Van Morrison, Robert’s favorite rocker. “Everything blended together really well.”

Sounds fun, but I hope the hotel has good sound proofing! Maybe the New Moon cast should invest in a practice space in Vancouver while they’re in town? Any suggestions on band names? The Grateful Undead? All Hale Breaks Loose? Vampire Weekday? I could go on.