Alicia Keys shows off her enviable derriere as she takes to the stage in tiny crop top and skin tight trousers

PUBLISHED: 17:45 EST, 28 September 2012 | UPDATED: 18:12 EST, 28 September 2012

With the iTunes festival coming to a close the big music guns have come out to play.

Alicia Keys took to the stage at The Roundhouse in Camden to show off her stellar singing skills.

The American star showed off her trim shape in a figure-hugging outfit, consisting of a pair of high-waisted trousers and a cropped vest top.

Skimpy stage style: Alicia Keys performed in a cropped vest and a pair of tight high-waisted trousers at the iTunes festival at the Roundhouse in Camden tonight

The outfit accentuated her ample derriere, which she paraded around the stage as her set played out.

Alicia, 31, wore a gold serpent necklace around her neck and a pair of killer high heels to perform.

Following the performance Alicia tweeted: 'It was a packed house and I'm sure there were more of you watching at home! So blessed!!! #itunesfestival.'

She's got some curves: The 31-year-old singer showed off her impressive bottom in a pair of figure-hugging tight black trousers

Impressive talent: Alicia belted out some of her hit tunes at the Roundhouse in Camden

This morning Alicia paid a visit to Radio 1 to appear on the breakfast show to promote her latest album Girl On Fire.

Alicia appeared to have plenty of fun with new presenter Nick Grimshaw and the pair took a series of photo booth snaps as a memento of their time together.

The mother-of-one tweeted: 'Early morning radio in London rockin out w @grimmers!!! Tired but laughin!'

The singer has been in the UK all week and performed a free gig in Manchester's Cathedral.