Who? Formed in Reykjavik, Iceland in 1994, Sigur Ros released one critically acclaimed album (along with an LP of remixes the following year) in their homeland before going international with the release of Ágætis Byrjun in 1999, which quickly catapulted them onto the radar of American and European music fans.

Broken Social Scene got an early start Sunday, appearing at Bonnaroo's tiny Solar Stage for a quick, half-hour prequel to their proper set later that evening.

As anxious fans squeezed their way to the front of That Tent in the early A.M. hours Sunday, Sigur Rós appeared under eerie blue lighting and enormous illuminated hanging balloons to deliver two hours of epic musical ecstasy, leaving everyone in the crowd speechless and, quite literally, waiting for more.

Jakob Dylan and the Gold Mountain Rebels, which includes Nashville-based guitarist Audley Freed and drummer Fred Eltringham, appeared during the height of Sunday's heat wave and attempted to cool things down at Bonnaroo's This Tent.

Just when it seemed Saturday couldn't get any hotter, Sharon Jones and the Dap Kings took to Bonnaroo's Which stage, grooving and popping their way through an hour-long set that had even the stiffest fans shaking like there was no one looking.

Concord, North Carolina's Avett Brothers drew a massive (and especially rowdy) crowd to Bonnaroo's Other Tent Saturday, picking and stomping their punk-tinged bluegrass into the stratosphere and proving why they just may be one of the most underrated acts at this year's festival.