Gates open at 1 p.m.

Cellular South Stage

2 p.m., Billy Lee Riley: Sun Records veteran Billy Lee Riley is the odd man out today on the Cellular South Stage, sharing the bill with a crew of light pop purveyors. Although Riley’s known for his own tongue-in-cheek numbers (”Red Hot,” “Flyin’ Saucers Rock ‘n’ Roll”) he remains a rockabilly heavyweight, capable of knocking out audiences at a still spry 73 years old.

3:30 p.m., Umphrey’s McGee: This fast rising Midwest sextet has been tagged as the “next Phish” due to its popularity with jam band audiences. The group, which released the well-received Safety In Numbers in 2006, followed with a disc of leftovers from the sessions, The Bottom Half, earlier this year.

5:15 p.m., Guster: Boston-based Guster made its name in late-’90s college rock circles playing with a stripped-down set-up (a pair of acoustic guitars and hand percussion). Since then, the fan-friendly act has expanded its line-up and sound, moving beyond its early jam style into more layered alt-pop explorations.

7 p.m. Barenaked Ladies: This Canadian joke-pop outfit, often described as a poor man’s They Might Be Giants, remains popular almost a decade after breaking out in the States with radio hits like “One Week,” “Pinch Me” and “Brian Wilson.” The group is reportedly in the process of compiling tracks for a box set due later this year.

8:45 p.m. Counting Crows: The Counting Crows have been turning out its signature brand of jangly, melancholy pop since the early ’90s. Along the way the band has sold over 20 million records worldwide and been nominated for an Academy Award (for its contribution to the “Shrek 2″ soundtrack). Last year the group released its second concert collection, New Amsterdam: Live at Heineken Music Hall 2003. The group has also been back in the studio, working on a new album with Pixies producer Gil Norton.

Budweiser Stage:

2:10 p.m., Companyia Electrica Dharma: This instrumental outfit from the Catalonia region of Spain is part of the festival’s mission to honor the country. The five-piece group, led by brothers Esteve, Joan and Josep Fortuny, has been earning raves for their sprite brand of European jazz-fusion.

3:55 p.m., Ann Peebles: Soul songstress Ann Peebles made her reputation as a part of the Hi Records family in the 1970s. But Peebles’ work has remained prominent in popular culture, thanks to sampling by numerous rap acts, including members of the Wu Tang Clan. Last year, Peebles released Brand New Classics, on which she re-cut some of her hit songs in a stripped-down acoustic style.

5:30 p.m., Edwin McCain: South Carolina singer-songwriter Edwin McCain rode in on the wave of success created by his hometown friends Hootie and the Blowfish. Landing a record deal with Atlantic in the mid-’90s, he sired the hit “I’ll Be,” launching a career that’s boasted 10 albums of soulful pop, including his latest Lost in America, released on Vanguard last year.

7:40 p.m. Corinne Bailey Rae: The Leeds, England-born singer-songwriter charmed the U.K. last year and has done the same here in the States. Playing a brand of jazz-inflected soul, Rae’s self-titled debut earned her a trio of Grammy nominations and has sold 3 million records worldwide.

9:10 p.m., John Legend: R&B piano man John Legend has successfully navigated the worlds of soul, rap and pop during his meteoric rise to the top of the contemporary music scene. A five-time Grammy winner, Legend’s work with the cream of the hip-hop world (Snoop Dogg, Kanye West, Jay-Z) has been balanced by his own gospel and classical background, the combination proving chart gold for the singer on his first two platinum efforts, 2004’s Get Lifted and 2006’s Once Again.

AutoZone Stage

2 p.m., Alison Heafner: Local up-and-comer Alison Heafner kicks off Sunday’s festivities with a set of soulful Southern rock. With a voice pickled in whiskey and cured in Kools, Heafner admirably carries the torch of female forebears like Janis Joplin and Bonnie Bramlett.

3:10 p.m., Egypt Central: This Memphis alt-rock act, led by singer John Falls, has had its ups and downs over the years. The group drew national attention signing a deal with Atlantic/Lava only to see its label imprint close and have its album shelved. The band has bounced back, releasing a debut CD to brisk sales, landing a tune on the soundtrack to the Steve Austin flick “The Condemned,” and growing a loyal local following.

4:45 p.m., Papa Roach: Fronted by Jacoby Shaddix, these popular California-based nu-metal hitmakers were responsible a string of chart records including the 2000 high-water mark Infest. The group softened and sweetened on more recent albums, including last year’s The Paramour Sessions .

6:20 p.m., Project Pat: Three 6 Mafia collaborator Project Pat branches out for a solo set, sure to draw on last year’s Crook by the Book: The Fed Story, a heavily autobiographical song cycle released after his lengthy imprisonment.

7:35 p.m., Daughtry: The vehicle for “American Idol” alum Chris Daughtry, the singer formed this muscular alt-rock group in 2006 after his fourth-place finish on the popular TV talent show. The group’s first album, released in November, is the fastest selling debut in SoundScan history.

9:05 p.m., Hinder: Oklahoma hard rockers specializing in a fun, mindless brand of sex, drugs and rock-and-roll hedonism. Catching the attention of Universal Records after a successful independent EP, the group released its major label debut, Extreme Behavior, which has since gone double platinum and spawned the hit singles “Lips of an Angel” and “How Long.”

TN Lottery Blues Stage

2 p.m., James “Supa Chikan” Johnson: A nephew of the great guitarist “Big” Jack Johnson, James “Supa Chikan” is a multimedia outsider artist who happens to play a mean boogie blues on a variety of homemade instruments, mixing outre spoken word elements into his songs as well.

3:20 p.m., The Lee Boys: A family gospel group from Florida, The Lee Boys specialize in a brand of sacred steel music popularized by Robert Randolph. Though faithful to the traditions of the genre, they suffuse their sound with dashes of jazz, funk, world and even hip-hop, creating a potent sonic stew.

4:50 p.m., Watermelon Slim: North Carolina-based Bill “Watermelon Slim” Homans and his group, the Workers, have been a breakout success in the blues world. The group leads the 2007 Blues Awards with a record-tying six nominations for their self-titled album. Homans’ authentic lap slide playing and vocal stylings are even more fascinating when you consider his varied personal background as a Vietnam vet, an accomplished academic and an active member of high-I.Q. society, Mensa International.

6:25 p.m., Backdoor Slam: Led by 19-year-old guitar wizard Davy Knowles, this British blues power trio hails from the Isle of Man. Working a sound not unlike John Mayall’s classic Bluesbreakers line-ups and Peter Green-era Fleetwood Mac, their debut CD, Roll Away, will be released this summer on Blix Street records.

7:45 p.m., Tab Benoit: The Houma, La.-bred guitarist and singer has been a longtime Memphis favorite. Though he’s often been paired with disparate musicians and producers over the course of his career, Benoit has remained loyal to his Cajun roots on albums like Wetlands, Fever for the Bayou and 2005’s Brother to the Blues, which was nominated for a Grammy. A tireless road warrior, Benoit continues to dazzle audiences with his swampy take on modern blues.

9:20 p.m., Elvin Bishop: Though he’ll probably be best remembered for his 1976 pop hit “Fooled Around and Fell In Love,” Elvin Bishop has been at the cutting edge of the modern blues world, dating back to his early days as a member of Paul Butterfield’s classic band. In the late ’80s, Bishop returned to more roots-oriented releases, like his last album, the emotionally charged 2005 effort Gettin’ My Groove Back.