Martha Wainwright will be joining Paolo Nutini for the fifth Eden Session on July 13.
Martha and Paolo are added to a blockbuster bill alongside Jack Johnson (June 26 - sold out), Mika (June 27), Doves and Mumford & Sons (July 2 - sold out) and Calvin Harris and Audio Bullys (July 3) with more to be announced.
The Canadian-American singer-songwriter released her acclaimed self-titled debut album in 2005, and was also given positive reviews for her 2008 record I Know You're Married But I've Got Feelings Too, which featured a guest appearance by Pete Townshend of The Who among others.
Last year saw the release of Sans Fusils, Ni Souliers, A Paris: Martha Wainwright's Piaf Record, in which the singer stamps her own identity on the songs of Edith Piaf.
In the UK, Martha may be best known for her duet with previous Sessions artists Snow Patrol on the top-20 song Set the Fire to the Third Bar.
The Canadian-American singer comes from a legendry music family. Her father is American folk singer and actor Loudon Wainwright III and her mother Canadian folk singer-songwriter Kate McGarrigle.
Her older brother Rufus is no stranger to the Eden Project, receiving critical acclaim for his headlining Sessions appearance in 2007.
The 2010 Sessions will be the ninth season of summer gigs at the Eden Project. Performers in previous years include Oasis, Kasabian, Florence and the Machine, Vampire Weekend, Paul Weller, Hot Chip, Muse, Editors, Snow Patrol, Basement Jaxx, Amy Winehouse, Moby, PJ Harvey and The Verve.
Tickets for the Paolo Nutini Session go on general release at 6pm tomorrow (Tuesday March 23). They are priced at £35 plus booking fee.
To buy tickets visit www.edensessions.com or call the Eden box office on 01726 811972.
