FILE - This Feb. 20, 2013 file photo shows Kacey Musgraves at the Barista Parlor in Nashville, Tenn. Musgraves will be performing at the Bonnaroo Music and Arts Festival that begins Thursday, June 13 and runs through Sunday. Photo by Donn JonesInvision/AP, file (AP) - The headliners usually get all the ink and this year's group at the Bonnaroo Music & Arts Festival is definitely ink-worthy: Paul McCartney, Mumford & Sons and Tom Petty. It's the down-list acts, though, that make this a particularly strong Bonnaroo lineup with a number of must-see acts you ought to check out before they're so big you'll be standing at the back of the crowd watching them on the video screens. Here are 10 to see: Alt-J: This Mercury Prize-winning quartet plays angular pop songs that are oddly intoxicating. Like fellow Brits McCartney and Mumford, the group has a gift for sugary songs that are impossible to resist. Action Bronson: The burly, bearded rapper from Queens is poised to release his major-label debut later this year and has been whipping up a frenzy in London before returning to the states for Bonnaroo. Expect stage diving, East Coast harmonics and lots of naughty humor. Charli XCX: The alternapop princess has had the bloggers buzzing for a couple of years. Now she's attached to a worldwide hit - she features on Icona Pop's "I Love It" - and has the highest profile of her career coming into Manchester. Father John Misty: Former Fleet Foxes drummer Josh Tilman left the band and released his first solo album under this new moniker after several releases as J. Tilman. "Fear Fun" was on many year-end lists and it will be interesting to see how far Tilman's mostly hushed folk-rock will carry at Bonnaroo. HAIM: Los Angeles-based sisters Este, Danielle and Alana Haim form a girl group for the 21st century, mixing lush vocal harmonies with high energy, beat-oriented grooves that have won over a lot influential fans. They're managed by Roc Nation, recently collaborated with Diplo and Kid Cudi, and are working on a debut album. Jason Isbell: The Alabama-raised, Nashville-based singer-songwriter is the Americana community's cause celeb du jour. He releases his new album "Southeastern" this week, just in time to take his brand of Southern rock to the masses. Japandroids: Just when you think the two-man band thing has run its course, up pops Vancouver-based Japandroids, a band guaranteed to generate more decibels per band member than any other on the farm. Their soaring, anthemic rock is perfect for Bonnaroo. Kacey Musgraves: Bonnaroo has had its share of edgy country acts over the years and Musgraves keeps the tradition rolling. This champion of Nashville songwriters has the off-kilter, left-leaning world view that fits right in at the festival. Portugal. The Man: This Portland-based band of spacey rockers has joined with producer Danger Mouse on its fun new album, "Evil Friends." Fans at Bonnaroo will be hearing the new music for the first time. There will be buzz. Tame Impala: Australian rocker Kevin Parker is the premiere purveyor of freaky, fuzzed-out psychedelic rock at the moment. Last year's "Lonerism" was one of rock's most praised albums and Bonnaroo could be a defining moment.