The monster of all festivals lives: Bonnaroo has begun. While A-list rock, pop and hip-hop names like Elton John, Jack White and Kanye West may rule the top of this year's lineup card, the eclectic festival, held 60 miles south of Nashville in Manchester, Tennessee, does showcase its share of country music. Chief among them: Dierks Bentley, a 2007 'Roo alumnus, is slated to burn a little 'grass as part of the Ed Helms' Bluegrass Situation Superjam on Sunday night. As the four days of live music, public intoxicants and increasingly dirty tents roll on, Rolling Stone Country looks back at some of the most memorable country moments — Kenny Rogers jamming with Phish! — that festival-goers are almost certain happened.