The new acts will join headliners Bob Dylan (UK exclusive), Peter Gabriel and The New Blood Orchestra (UK exclusive) and Suede (UK festival exclusive).
The latest artists to be announced are:
Richard Ashcroft (only Uk Show), Kool and the Gang, George Clinton Parliament Funkadelic, Randy Crawford and Joe Sample Trio, The Levellers, The Futureheads, Gilbert O'Sullivan, Ian Hunter, Gary Numan, Bellowhead, British Sea Power, The Tallest Man on Earth, Gomez, Howling Bells, Peter Hook and the Light.
Gruff Rhys, King Charles, Marcus Foster, Lights, Tanita Tikaram, Mary Coughlan, The Datsuns, Field Music, Treetop Flyers, Various Cruelties, Little Barrie , Cashier No 9, Robert Francis, Jonquil, Mary Epworth, James Levy and the Blood Red Rose, The Sheepdogs, Dan Clews, Helen Boulding, Noah Francis, Yossarian, Flight Brigade and Maia & Holy Something.
The festival which takes place June 29 - July 1 in Kent has also announced a new Powers Bar Stage and the first comedians confirmed for the Comedy Stage.
The comedians so far include: Russell Kane, Patrick Monahan, Phil Nicol, Kerry Godliman, Andy Zaltzman, Simon Evans, Ray Peacock MC, Carey Marx, Stephen Grant, Vikki Stone, Joey Page, Jolly Boat and Sion James.
Powers Stage acts are: Missing Andy, Washington Irving, Hares, The Joker & The Thief, Joel Sarakula, Daniel Fell, Yngve & The Innocent, The Midnight Barbers, Like Spinning, The A Train, Andy Docherty & The Caped Crusaders, Alan Medley, Kate Stapley, Julie Hawk, George Frakes, Inti Rowland.
Vince Power said: "I'm very happy with the bill. We have yet again put together a unique line-up of acts you're not going to see repeated anywhere else.
"We have some true legends including Patti Smith and Randy Crawford and I think that's what music fans look for; a well though out bill which is the best value festival this year."