447 events featuring 563 artists [195 headliners] (those in italic were never headliners):

53. Bob Dylan
15. Hannah Scott
14. Laura Marling, Patti Smith
13. Richard Thompson
12. Bruce Springsteen, Robyn Hitchcock
11. Ryan Adams, Slow Club
8. Neil Young
7. Felice Brothers, KT Tunstall, Mark Knopfler, Nick Cave, Pete Doherty
6. Brian Wilson, Martyn Joseph, Sharon Van Etten
5. Ben Folds, Billy Bragg, John Cale, John Murry, Kami Thompson, Kimberley Rew, Lucinda Williams, Model Village, Simone Felice, Waterboys
4. Anais Mitchell, Craig Finn, John Bramwell, Kate Rusby, Lou Reed, Loudon Wainwright III, Martin Carthy, Rails, Tallest Man On Earth, This Is The Kit, Webb Sisters
3. Adam Green, Babyshambles, Benmont Tench, Cardinals, Chuck Prophet, Conor Oberst, Eliza Carthy, Elvis Costello, Emma Kupa, Graham Nash, Gruff Rhys, Heritage Orchestra, Hold Steady, I Am Kloot, Jack White, Jesca Hoop, Jesse Malin, Natalie Prass, Neal Casal, Nick Barraclough, Paul Brady, Peter Bruntnell, Promise Of The Real, Ronnie Wood, Rozi Plain, Seth Lakeman, Steve Earle, Van Morrison
2. Al Jardine, Allison Moorer, Arthur Lee, Belle and Sebastian, Ben Folds Five, Ben Glover, Beth Orton, Bitter Ruin, Blair Dunlop, 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 and the Champions of the World, Dave Rawlings, Devon Sproule, Ed Harcourt, Emma Gatrill, Emma Swift, Ethan Johns, First Aid Kit, Frank Turner, Fred Abong, Gill Landry, Gillian Welch, Grant-Lee Phillips, Howe Gelb, Jake Bugg, Jarrod Dickenson, Jeffrey Lewis, Jenny Adajeyan, 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, Martin Harley, Mary Gauthier, Mastersons, Matthew E. White, Mick Taylor, Modeste Hughes, Nadia Reid, Nadine Shah, Nick Mulvey, Nigel Stonier, Patrick Wolf, Paul McCartney, Paul Weller, Pippa Evans, Ralph McTell, Randy Newman, Regina Spektor, Roger Daltrey, Rolling Stones, Roy Harper, Samantha Parton, Seamus Fogarty, Seasick Steve, Simi Stone, Sinead O'Connor, Southside Johnny, Stray Birds, Sweet Baboo, Terry Edwards, Thea Gilmore, Thurston Moore, Tom Petty, Tony Joe White, Willy Mason, Wizz Jones, Zack Hobbs
1. A. A. Bondy, Abi Wade, Addie Brownlee, Adolphus James, Alan Fletcher, Alasdair Roberts, Aldous Harding, Alessi's Ark, Alfie Jones, Ali McKenzie, Alison Krauss, Alistair Anderson, Allman Brown, Allo Darlin', Amanda Palmer, Amazing Snakeheads, Amy LaVere, Andy Burrows, Andy Irvine, Andy Jenkins, Anna Hester, Annie Dressner, Attic Lights, Auld, Avi Buffalo, 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 Ryder-Jones, Bill Wyman, Billy Lockett, Birds of Chicago, Bittersweets, Black Crowes, Black Feathers, Blazing Zoos, Blind Boys of Alabama, Blondie Chaplin, Bluetones, Bob Frank, Bob Mould, Bonnie Prince Billy, Boomtown Rats, Bourgeois and Maurice, Bricolotheque, Bright Eyes, Britta Persson, Brodka, Bruce Cockburn, Buke and Gass, C Joynes, Calexico, Camera Obscura, Cara Dillon, Caravan, Carsie Blanton, Case Hardin, Cat Power, Cate Le Bon, Centimes, Chaim Tannenbaum, Charles Watson, Chloe Foy, Chris Fox, Chrissie Hynde, Christine Collister, 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 Pegg, Dave Swarbrick, Dave Woodhead, David Gilmour, Dawes, Delays, Delta Maid, Derek Smalls, Dive Dive, Dodge Brothers, Dom Prag, Don Was, Dot Allison, Doves, Eddie Thornton, Eleanor McEvoy, Elinor Alicia, Emily Barker, Emily Maguire, Emma Smith, Emma Trica, Emmylou Harris, Eric Bibb, Eric Cantona, Eric Clapton, Esya, Ethan Ash, Euros Childs, Everest, Fall, Family, Fat White Family, Fisherman's Friends, 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, Glen Hansard, 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, Holy Now, Hot Puppies, Howard Ivans, Hudson Taylor, Hugh Cornwell, Hyde and Beast, Ian Felice, Ibeyi, In Fear Of Olive, Ipso Facto, Iron & Wine, Jack Watts, Jackson Browne, James Heather, James Morrison, Jan Bell, Jarlath Henderson, Jasmine Kennedy, Jasmine Rodgers, Jason Isbell, Jay Fraser, 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, Judith Owen, Julie Byrne, Kaia Kater, Karl Blau, Karmadillo, Kathryn Tickell, Kathryn Williams, Katie Malco, 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, Linda Thompson, Living Room, Lloyd Cole, Local Honeys, London Contemporary Orchestra, Los Lobos, Lowell Levinger, Lowpines, Loyle Carner, Lucy Gaffney, Lucy Wainwright Roche, Lumineers, Lump, Lydia Bayliss, Lydia Ramsey, Lyla Foy, MG Boulter, Macaulay Culkin, Maddy Prior, Mahalia, Maisy Beth, Malakai, Mammoth Penguins, Marc Ellington, Marissa Saroca, Mark Gamon, Marry Waterson, 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, Nicole Atkins, Nils Lofgren, Nina Nesbitt, Nina Violet, Nitty Scott, Noah and the Whale, Oka Vanga, Old Crow Medicine Show, Olivia Chaney, 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, 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 Brookes, Sam Carter, Sam Fender, Sam Sallon, Sam Sweeney, 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, Simeon Jones, 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, Strawberry Generation, Supergrass, Supermoon, Surfing Magazines, Tanya Boutte, Tape Runs Out, Tarantula Waltz, Teddy Thompson, Teenage Fanclub, Teitur Lassen, Thirst, Thrills, Tim the Mute, Timber Timbre, Tiny Dancers, Tom Morello, Tom Odell, Tom Robinson, Tom Waits, Unthanks, Valerie June, Van Dyke Parks, Vandeville Falls, Vardo and the Boss, Victor Velocette, Violent Femmes, Wave Pictures, White Rabbits, Who, Wiggy, Wild Beasts, Wilko Johnson, William Crighton, Willy Porter, Winter, Wintersleep, Wolfman, Ye Vagabonds, Young Waters, Zara Phillips, yMusic