Big Ears audiences who find themselves at Clogs' Saturday afternoon set at the Bijou to see indie-folk superstar Sufjan Stevens (in his only scheduled appearance at the festival) may be in for a surprise. Though fans of Stevens' tastefully indulgent arrangements won't be completely lost up against Clogs' wispy, varied chamber music (arranged primarily for viola, guitar, bassoon, and percussion), they may find it one of the most pleasantly challenging of the weekend's events. As weird as Clogs' newest album The Creatures in the Garden of Lady Walton is, though, it's brought the largely instrumental quartet closer than ever to the realm of pop, mostly through guest vocalists like Stevens, My Brightest Diamond's Shara Worden, and the National's Matt Berninger. (Clogs' multi-instrumentalist leader Padma Newsome has long been responsible for the National's string arrangements, and guitarist Bryce Dessner plays in both bands.) The presence of all of Lady Walton's collaborators at Big Ears 2010 is extra-significant, as it provides a venue for what may be the group's last performance for some time, as Dessner and Newsome set out on tour with the National and the other members get back to other projects. "It's really going to be a special event, for us at least," Dessner says. "It's a great moment to do it."