Guster are currently on the road with Barenaked Ladies and Ben Folds Five as part of the second annual Last Summer on Earth Tour. The extended run has featured a few regular collaborations, mostly during Barenaked Ladies’ headlining set. For instance, on Monday night at Columbia, MD’s Merriweather Post Pavilion, Guster drummer Brian Rosenworcel sat in with Barenaked Ladies for “Brian Wilson,” Guster singer/guitarist Ryan Miller emerged for “Gonna Walk” and Folds returned to the stage for the early Barenaked Ladies hit “If I Had $1,000,000.” Comedian Boothby Graffoe also joined Barenaked Laides onstage for “Be My Yoko Ono.”

In addition, Guster welcomed a surprise guest during their opening set at Nashville, TN’s The Woods Amphitheater at Fontanel. Partway through their performance, Guster brought out longtime friend and Nashville transplant Ben Kweller for a take on “I Hope Tomorrow Is Like Today.” Keller appears on the studio version of the Keep It Together track.

The Last Summer on Earth Tour continues in Philadelphia, PA tomorrow.