The Magic Numbers are among the latest names added to the Hard Rock Calling line-up.
The siblings band will be joined by anti-folk heroes Johnny Flynn and Mumford And Sons on the Saturday (27 June) along with Priscilla Ahn.
Howling Bells have been confirmed for the Friday (26 June) with Metric and Silversun Pickups also announced for the Pepsi Max Stage.
On the final day of the event (28 June) Starsailor, The Low Anthem, Joshua Radin and Pretty Things have all be added to the bill.
The Killers, Neil Young and Bruce Springsteen will headline Hard Rock Calling 2009 which takes place at Hyde Park, London from 26-28 June.
Tickets are on sale now priced at £45 per day. Click here to buy Hard Rock Calling tickets.