Confirmed Bonnaroo lineup announced during live online event

Revelers shower beneath the Fountain during the Bonnaroo Music & Arts Festival on Saturday, June 14, 2014, in Manchester, Tenn.
Revelers shower beneath the Fountain during the Bonnaroo Music & Arts Festival on Saturday, June 14, 2014, in Manchester, Tenn.
Live Blog 2015 Bonnaroo Lineup Announcement

9:15 p.m. update:

The Bonnaroo Music & Arts Festival announced its 2015 lineup during a three-hour online event known as the Bonnaroo Line-up Announcement Megathon Tuesday night. Fans had the opportunity call into a toll-free number to get the name of one act, and to then post that name on Twitter, Instagram or Vine.

When it's all said and done, the 2015 Bonnaroo Music & Arts festival will feature 125 musical acts and 20 comedians performing on 12 stages over four days in June.

Headliners are Billy Joel, Mumford & Sons, Deadmau5, Kendrick Lamar, Florence and The Machine, Robert Plant and The Sensational Space Shifters, My Morning Jacket, Bassnectar and Alabama Shakes.

The lineup includes a mix of independent acts, established favorites and oldies acts such as R&B favorites Earth, Wind & Fire, thrash metal band Slayer and MTV video faves Tears For Fears.

Several acts such as Alabama Shakes, My Morning Jacket, which played an epic four-hour early morning set in 2008, Plant, Ed Helms and Belle and Sebastian, are making repeat appearances.

The complete announced schedule is:

Childish Gambino, Flume, Hozier, Slayer, Ben Harper & The Innocent Criminals, Belle and Sebastian, Spoon, The War On Drugs, STS9, Ben Folds and Atmosphere.

Atomic Bomb! Who Is William Onyeabor?, Tears for Fears, Brandi Carlile, Twenty|One|Pilots, The Bluegrass Situation SuperJam featuring Ed Helms & Special Guests, Flying Lotus, Earth Wind & Fire, Caribou, Gary Clark Jr., SBTRKT, Punch Brothers, Medeski, Scofield, Martin & Wood, Tove Lo, Run the Jewels, Dawes, G-Eazy, Trampled By Turtles, Sturgill Simpson and Moon Taxi.

AWOLNATION, Sylvan Esso, Bela Fleck & Abigail Washburn, Guster, Jamie XX, Against Me!, Odesza, SOJA, Jerry Douglas Presents Earls of Leicester, Bleachers, Rudimental, Mac DeMarco, Tycho, The Very Best, Freddie Gibbs & Madlib, Shakey Graves, Shabazz Palaces, Gramatik, M, Unknown Mortal Orchestra, Jungle, Benjamin Booker, Houndmouth, The Growlers, Glass Animals, Ana Tijoux, SZA, Courtney Barnett, Rhiannon Giddens, Royal Blood and Tanya Tagaq.

Woods, Hurray For The Riff Raff, Iceage, Temples, Between The Buried & Me, Rustie, Ryn Weaver, Dopapod, Pokey LaFarge, Priory, Bahamas, Strand of Oaks, Phox, Gregory Alan Isakov, Brownout Presents Brown Sabbath, The Districts, Madisen Ward & Mama Bear, DMA's, Catfish & The Bottlemen, Jon Cleary & The Monster Children, Pallbearer, Dej Loaf, Christopher Denny, Hiss Golden Messenger, King Gizzard and The Lizard Wizard, Jessica Hernandez & The Deltas and Unlocking the Truth.

Tickets go on sale at noon on Jan. 17. The festival, which takes place in Manchester, Tenn., is set for June 11-14.

8:48 p.m. update:

The Bonnaroo Line-up Announcement Megathon is underway in a chaotic explosion of social media announcements. Fans are calling in to a phone number and are told the name of one act. They are then encouraged to post that information to Twitter, Instagram and Vine.

Headlining will be Billy Joel, who has never appeared at the festival.

Other confirmed acts include Mumford and Sons, Robert Plant and the Sensational Space Shifters, Slayer, Florence and the Machine, Tears For Fears, Belle and Sebastian, Spoon, Run the Jewels, Gary Clark Jr., Earth Wind & Fire, Bassnectar, Ben Harper & The Innocent Criminals, Against Me!, Flying Lotus, Caribou, The War on Drugs, Dawes, Mac DeMarco, Freddie Gibbs and Madlib, Shabazz Palaces, SBTRKT, Jamie xx, Courtney Barnett, Benjamin Booker, Rustie, Hozier, STS9, Bleachers, Flume, Sturgill Simpson, Sylvan Esso, Rudimental, Strand of Oaks, Unknown Mortal Orchestra, Woods, Tycho, The Bluegrass Situation Superjam hosted by Ed Helms, Ryn Weaver, Bela Fleck and Abigail Washburn, Gramatik, Brandi Carlile, Rhiannon Giddens, Guster, Houndmouth, Medeski, Scofield, Martin & Wood, Punch Brothers, Trampled By Turtles, Jerry Douglas presents Earls of Leicester, Shakey Graves, The Very Best, Twenty One Pilots, G-Eazy, Odesza, Moon Taxi, SOJA, Glass Animals, Jungle, The Growlers, Bahamas, Temples, Pokey LaFarge, and Tove Lo.

Some of these acts, such as Plant, Bassnectar and Trampled by Turtles are returning acts.

A cursory glance at that list confirms that Bonnaroo has again sought diversity. Joel is a pop icon known for his piano-based hits. Mumford is at the forefront of the newer banjo infused rock. And then you have electronic music from Bassnectar, the R&B of Earth Wind & Fire and MTV video era hits of Tears for Fears.

Another Bonnaroo tradition has been to bring back bands that grow in stature over the years. Numerous acts first played there on the smaller stages. Alabama Shakes is such an act. They are listed among the top-tear acts this year and will likely play on either the Which or What stages as the two largest venues are called. Mumford and Sons is another such act.

ORIGINAL STORY FOLLOWS:

It has become traditional for the Bonnaroo Music & Arts Festival to announce its lineup in a big way via something they call the Bonnaroo Line-up Announcement Megathon, or B.L.A.M., and this year is no different.

Fans can call 1-844-ROO-2015 from 6-9 p.m. to find out the name of one artist in the lineup. They are then asked to share the name on Twitter, Instagram or Vine with a sign, a short video or any other creative means using the ashtag #Bonnaroo. Those will be compiled on the bonnaroo web site.

The announcement comes almost a month earlier than in past years, and comes within days of schedules for Coachella Valley Music and Arts Festival in California, the Hangout Festival in Gulf Shores, Ala., Shaky Knees(being announced Jan. 14) in Atlanta being announced.

In 2013, Weird Al Yankovic hosted the B.L.A.M. event. Last year, Ben Folds, Taran Killam, Hannibal Buress and The Flaming Lips were part of the announcement festivities.

Bonnaroo is set for June 11-14 in Manchester, Tenn. Tickets go on sale at noon on Jan. 17.