San Francisco’s Outside Lands Music and Arts Festival officially kicks off today in Golden Gate Park. The festival—now in its fourth year—will feature performances from headliners Phish, MGMT, Arcade Fire and Muse as well as art, food and wine events over the course of the weekend. On a recent press call, two of the festival’s performers—Mark Foster of Foster the People and Decemberists bassist Nate Query—chatted with journalists about their plans for the festival, bands they are excited to see and even some potential collaborations.

Foster admitted “You know, I’ve never owned a Phish record but I’ve always heard amazing things about their shows. So I’m looking forward to seeing them for sure. I think it’s amazing, you know, the musicians shift when a band goes up and they never play the same set twice—they just kind of breathe their instruments.” Foster the People may also cover Weezer’s “Say It Ain’t So,” a song Foster says Rivers Cuomo taught him at a party when he was only 18. Foster added the song to his band’s repertoire after Weezer started covering Foster the People’s hit single, “Pumped Up Kicks”

The Decemberists bassist, who admitted to once playing in a jamband of his own, discussed some of the weekend’s potential sit ins. “We could very do something with Mavis again. She’s always up for it. And then we’re playing right before Arcade Fire. You know, maybe we’ll have a few extra drummers on a song or something.”

The festival gates open at 11AM PDT today and the music begins one hour later. The complete schedule is available at the Outside Lands website.