421 events featuring 520 artists [186 headliners] (those in italic were never headliners):

51. Bob Dylan
15. Hannah Scott
13. Patti Smith
12. Bruce Springsteen, Laura Marling
11. Richard Thompson, Robyn Hitchcock, Ryan Adams, Slow Club
7. Felice Brothers, KT Tunstall, Mark Knopfler, Pete Doherty
6. Brian Wilson, Martyn Joseph, Neil Young, Nick Cave
5. Ben Folds, John Cale, John Murry, Kimberley Rew, Sharon Van Etten, Simone Felice
4. Billy Bragg, Craig Finn, John Bramwell, Kami Thompson, Lou Reed, Lucinda Williams, Model Village, This Is The Kit, Waterboys, Webb Sisters
3. Adam Green, Anais Mitchell, Babyshambles, Benmont Tench, Cardinals, Chuck Prophet, Conor Oberst, Elvis Costello, Heritage Orchestra, Hold Steady, I Am Kloot, Jack White, Jesse Malin, Kate Rusby, Loudon Wainwright III, Martin Carthy, Natalie Prass, Neal Casal, Nick Barraclough, Paul Brady, Peter Bruntnell, Ronnie Wood, Rozi Plain, Seth Lakeman, Steve Earle, Tallest Man On Earth, Van Morrison
2. Al Jardine, Allison Moorer, Arthur Lee, Belle and Sebastian, Ben Folds Five, Ben Glover, Beth Orton, Bitter Ruin, Bobby Gillespie, Brian Fallon, Buick 6, Charlie Fink, Chris Wood, Christy Moore, Crazy Horse, Crooked Still, Crosby, Stills and Nash, Dan Bern, Dan Wilde, Danny Williams, Danny and the Champions of the World, Dave Rawlings, Devon Sproule, Ed Harcourt, Eliza Carthy, Emma Gatrill, Emma Kupa, Emma Swift, Ethan Johns, First Aid Kit, Frank Turner, Fred Abong, Gill Landry, Gillian Welch, Grant-Lee Phillips, Gruff Rhys, Howe Gelb, Jake Bugg, Jarrod Dickenson, Jenny Adajeyan, Jesca Hoop, Jessica Lee Morgan, Jolie Holland, Jonathan Wilson, Kate Miller-Heidke, Kathleen Edwards, Keir Nuttall, Kim Richey, Kristin Hersh, Krystle Warren, Larkin Poe, Laura Veirs, Leonard Cohen, Magazine, Mark Wynn, Martha Wainwright, Mary Gauthier, Mastersons, Matthew E. White, Mick Taylor, Modeste Hughes, Nadia Reid, Nadine Shah, Nigel Stonier, Patrick Wolf, Paul McCartney, Paul Weller, Pippa Evans, Rails, Randy Newman, Regina Spektor, Roger Daltrey, Rolling Stones, Roy Harper, Samantha Parton, Seamus Fogarty, Seasick Steve, Sharon Robinson, Simi Stone, Sinead O'Connor, Southside Johnny, Stray Birds, Sweet Baboo, Terry Edwards, Thea Gilmore, Thurston Moore, Tom Petty, Tony Joe White, Willy Mason
1. A. A. Bondy, Abi Wade, Addie Brownlee, Adolphus James, Alan Fletcher, Alasdair Roberts, Aldous Harding, Alessi's Ark, Ali McKenzie, Alison Krauss, Allman Brown, Allo Darlin', Amazing Snakeheads, Amy LaVere, Andy Burrows, Andy Irvine, Andy Jenkins, Anna Hester, Annie Dressner, Attic Lights, Auld, Avi Buffalo, BJ Cole, Baby Copperhead, Baby Dee, Barb Jungr, Barbarossa, Barns Courtney, Beach Boys, Bear's Den, Beck, Bedouine, Beggars, Bellowhead, Ben Walker, Ben Watt, Benjamin Folke Thomas, Berri Farley, Beth Hedges, Bhi Bhiman, Bill Callahan, Bill Wyman, Billy Lockett, Birds of Chicago, Bittersweets, Black Crowes, Black Feathers, Blair Dunlop, Blazing Zoos, Blondie Chaplin, Bluetones, Bob Frank, Bonnie Prince Billy, Boomtown Rats, Bourgeois and Maurice, Bricolotheque, Bright Eyes, Britta Persson, Brodka, Bruce Cockburn, Buke and Gass, C Joynes, Camera Obscura, Cara Dillon, Caravan, Case Hardin, Cate Le Bon, Centimes, Chaim Tannenbaum, Charles Watson, Chris Fox, Chrissie Hynde, Christof, Ciaran Lavery, Clare and the Reasons, Clinic, Cloud Boat, Cocoon, Cold War Kids, Coming Soon, Courteeners, Cranberries, Cymbals Eat Guitars, Damien Jurado, Damien Rice, Dan Coyle, Dan Michaelson and the Coastguards, Dan Raza, Dan Whitehouse, Daniel Lanois, Dave Fidler, Dave Matthews Band, Dave Swarbrick, Dave Woodhead, Delays, Delta Maid, Dive Dive, Dodge Brothers, Dom Prag, Don Was, Dot Allison, Doves, Eddie Thornton, Eleanor McEvoy, Elinor Alicia, Emily Barker, Emily Maguire, Emma Smith, Emmylou Harris, Eric Bibb, Eric Cantona, Eric Clapton, Ethan Ash, Euros Childs, Everest, Fall, Family, Fat White Family, Flamin' Groovies, Flaming Lips, Flea, Fleet Foxes, Florence Welch, Fly Golden Eagle, Foxygen, Frank Messina, Fred's House, Freddie Stevenson, Garron Frith, Gary US Bonds, Gaslight Anthem, Gavin James, Georgie, Geraint Watkins, Gil Scott-Heron, Girl Ray, Glasvegas, Glenn Hodge Banned, Goat Roper Rodeo Band, Gold Heart Assembly, Gold Star, Golden Filter, Graham Coxon, Green Gartside, Greg Varlotta, Grinderman, Guillemots, Gwenifer Raymond, Half Moon Run, Hannah Fisher, Hannah Georgas, Happyness, Harper, Hercules and Love Affair, Hot Puppies, Howard Ivans, Hudson Taylor, Hyde and Beast, Ian Felice, Ibeyi, In Fear Of Olive, Ipso Facto, Jack Watts, Jackson Browne, James Heather, James Morrison, Jan Bell, Jarlath Henderson, Jasmine Kennedy, Jasmine Rodgers, Jason Isbell, Jay Fraser, Jeffrey Lewis, Jenny and Johnny, Jim Ghedi, Jimmy Cliff, Jimmy Webb, Joan Armatrading, Joan Baez, Joan Shelley, Joe Bonamassa, Joe Brooks, Joe Henry, Joe McKee, Joe Purdy, John Fogerty, John Meed, John Otway, John Paul Jones, Johnny Depp, Jonathan Jeremiah, Joshua Tillman, Josienne Clarke, Kaia Kater, Karl Blau, Karmadillo, Kathryn Williams, Katie Spencer, Kieran Leonard, Kills, Kings of Leon, Kitty, Daisy and Lewis, Kris Drever, Lady Antebellum, Ladysmith Black Mambazo, Larks, Laura Jean, Led To The Sea, Lee Forsyth Griffiths, Lera Lynn, Liam Frost, Libertines, Lillian Boutte, Living Room, Lloyd Cole, London Contemporary Orchestra, Los Lobos, Lowell Levinger, Lowpines, Loyle Carner, Lucy Wainwright Roche, Lumineers, Lump, Lydia Bayliss, Lydia Ramsey, Lyla Foy, MG Boulter, Macaulay Culkin, Mahalia, Maisy Beth, Malakai, Marissa Saroca, Mark Gamon, Martin Harley, Martin Simpson, Master Musicians of Jajouka, Matt Blake, Matthew and the Atlas, Megan Henwood, Megson, Mi'ens, Mic Righteous, Michele Stodart, Mik Whitnall, Mike Excell, Mike Lindsay, Militant Girlfriend, Morris Windsor, Mountain Firework Company, Mumford and Sons, Muntu Valdo, My Morning Jacket, Nadine Khouri, Nathan Ball, National, Navaro, Neil MacDonald, Neko Case, Nell Bryden, Nels Andrews, Nic Dawson Kelly, Nick Harper, Nick Lowe, Nick Mulvey, Nicole Atkins, Nils Lofgren, Nina Nesbitt, Nina Violet, Nitty Scott, Noah and the Whale, Oka Vanga, Old Crow Medicine Show, Olivia McShane, Only Son, Palma Violets, Papa George, Paul Goodwin, Paul Simon, Pete Roe, Phantom Limb, Phil Jupitus, Phoebe Bridgers, Pictish Trail, Pierce Brothers, Pixies, Pokey LaFarge, Pony Collaboration, Primal Scream, Pure Beauty, RW Hedges, Ralph McTell, Randy Crawford, Ray Davies, Ray Lamontagne, Reuben Hollebon, Richard Digance, Richmond Fontaine, Robbie Boyd, Robert Ellis, Robert Plant, Roddy Woomble, Roger McGuinn, Ruby Muse, Rufus Wainwright, Saint Clair, Sam Amidon, Sam Carter, Sam Sallon, Sarah Siskind, Scott Matthews, Scout Niblett, Sean McGowan, Self Esteem, Serpent With Feet, Shakey Navel Bones, Sharon Lewis, Sheri Kershaw Band, Sherika Sherard, Shilpa Ray, Shires, Silver Mount Zion Memorial Orchestra, Sivu, Smoke Fairies, Soap and Skin, Sorren Maclean, Spinning Coin, Steve Harley, Steve Kopandy, Steve Van Zandt, Steve Winwood, Stevie Nicks, Stick in the Wheel, Stout Brothers, Stranded Horses, Supergrass, Supermoon, Surfing Magazines, Tanya Boutte, Tape Runs Out, Tarantula Waltz, Teenage Fanclub, Teitur Lassen, Thirst, Thrills, Tim The Mute, Timber Timbre, Tiny Dancers, Tom Morello, Tom Odell, Tom Robinson, Tom Waits, Valerie June, Van Dyke Parks, Vandeville Falls, Vardo and the Boss, Violent Femmes, Wave Pictures, White Rabbits, Who, Wiggy, Wild Beasts, Wilko Johnson, Willy Porter, Winter, Wintersleep, Wizz Jones, Wolfman, Ye Vagabonds, Young Waters, Zack Hobbs, yMusic