The 'Price Tag' singer had to cancel several summer dates due to emergency surgery on her left foot last month, after falling off stage during a gig rehearsal.
The iTunes Festival runs for 31 nights across July, and has already featured performances from the likes of Linkin Park, Arctic Monkeys and Beady Eye. Friendly Fires will be headlining at the Roundhouse tonight.
Hard-Fi will release their third studio album Killer Sounds on August 19.
Frontman Richard Archer recently revealed that the band were upset with the criticism of their last album Once Upon a Time in December.
Watch the video for Hard-Fi's 'Good for Nothing' below: