Soul diva Grace Jones and U.K. pop act Lily Allen are among the first acts announced to play at this year's open-air concert Summer Series at London's Somerset House.

The series kicks off with Jones on July 9, followed by Allen on July 11, U.K. alt-rock act the Ting Tings on July 14, Australian drum 'n' bass group Pendulum on July 15 and U.K. melodic rock outfit Athlete on July 17. The dates run until July 18, with further acts to be confirmed.

Somerset House has hosted its open-air summer concerts since 2003, featuring acts such as Bloc Party, Amy Winehouse, Duffy, Adele and the Prodigy. Metropolis returns as promoter for 2009.