Ed Sheeran, Jessie J and Mary J. Blige have been added to this year's iTunes Festival line-up.

The 'Sing' hitmaker has been announced to perform at the month-long series of gigs at The Roundhouse in Camden, north London, on September 29.

'Bang Bang' singer Jessie will perform on September 22 and US R&B star Mary will headline the September 25th show.

The trio join previously announced headliners Maroon 5, Sam Smith, Calvin Harris, Pharrell Williams and Kylie Minogue.

Ed said: ''I'm very happy to be playing my third iTunes Festival next month. I first played supporting Bruno Mars in 2011 and then came back the next year for my own.''

Mary added: ''I'm so happy to be playing for my first time at iTunes Festival. I've always loved visiting London and I can't wait to be back to see my UK fans next month.''

US crooner Tony Bennett - who is due to release an album with Lady Gaga - has also been announced for the festivities.

He commented: ''I'm thrilled to be back at iTunes Festival once again. It's a phenomenal musical experience for both the performers and the audience and I love being part of it!''

iTunes Festival 2014 line-up:

September 1 - deadmau5

September 2 - Beck and Jenny Lewis

September 3 - David Guetta, Clean Bandit and Robin Schulz

September 4 - 5 Seconds of Summer and Charlie Simpson

September 5 - Kasabian

September 6 - Tony Bennett

September 7 - Calvin Harris and Kiesza

September 8 - Robert Plant and Luke Sital-Singh

September 9 - Sam Smith and SOHN

September 10 - Pharrell Williams and Jungle

September 11 - Maroon 5, Matthew Koma and Nick Gardner

September 12 - Elbow and Nick Mulvey

September 13 - Paolo Nutini and Rae Morris

September 14 - David Gray and Lisa Hannigan

September 15 - The Script and Foxes

September 16 - Blondie and Chrissie Hynde

September 17 - Gregory Porter and Eric Whitacre

September 18 - Jessie Ware and Little Dragon

September 20 - Rudimental and Jess Glynne

September 21 - Ryan Adams and First Aid Kit

September 22 - Jessie J and James Bay

September 23 - Placebo

September 24 - Ben Howard and Hozier

September 25 - Mary J. Blige

September 26 - Lenny Kravitz and Wolf Alice

September 27 - Kylie and MNEK

September 28 - Nicola Benedetti, Miloš and Alison Balsom

September 29 - Ed Sheeran and Foy Vance