Pixie Lott, Ash, and The Futureheads will appear at Tramlines Festival in Sheffield.

The artists will be among over 600 acts to play across the city for free between July 22 and 24, in a showcase of both big names and up-and-coming acts from a cross section of genres, from heavy metal to dubstep.

Making extra-special appearances at the event will be a number of mystery local stars who will collaborate for a one off performance to open the festival on the Nokia Unannounced Stage, located at the city's Barkers Pool, on the Friday (22.07.11).

Sarah Nulty – one of the organisers of the festival - said: "Tramlines will start in style with some of Sheffield's musical heroes on the Nokia Unannounced Stage.

"We're very excited to see the special moments featuring both established and up-and-coming acts emerge from the Nokia Unannounced Tent."

The stage will then run throughout the weekend with more collaborations, acoustic performances and a silent disco.

The identities of acts opening the Unannounced Stage will be revealed at 9am on Friday July15 on Nokia's Facebook page, where fans can also win prizes including guaranteed entry to Tramlines and an event of their choice, a chance to meet the Unannounced Stage artists and more: facebook.com/nokia.uk