More big-hitters added to the month-long jamboree at London’s Roundhouse.

This week’s most talked about rapper and London’s own superstar MC have joined the bumper rollcall of acts playing September’s iTunes Festival. Kendrick Lamar will headline his own show on 19 September while Dizzee Rascal will perform on 27 September. Californian trio Haim are another new addition, playing on 21 September with support from Dan Croll.

Earlier this week Lady Gaga announced that she will kick off the series of shows on 1 September with an hour-long performance of all-new music from her forthcoming album ARTPOP.

They join a line-up that’s already packed with top drawer acts, including performances by Chic featuring Nile Rodgers, Janelle Monae, Sigur Rós, Justin Timberlake, Queens of the Stone Age and Pixies.

Tickets are only available to competition winners – find out more and how to apply at the iTunes Festival website. [via NME]

Here’s the line-up so far, with new additions in bold:

Lady Gaga (September 1)
Sigur Rós, Poliça (2)
The Lumineers, Phox (3)
Paramore, Fenech-Soler (4)
Rizzle Kicks (5)
Queens of The Stone Age, Palma Violets (6)
Phoenix, Little Green Cars (7)
Bastille, 1975 (8)
Arctic Monkeys, Drenge (9)
Jake Bugg, Valerie June (10)
Kings of Leon, Jimmy Eat World (11)
Elton John, Tom Odell (12)
Avicii (13)
Chic featuring Nile Rodgers, Janelle Monáe (14)
Vampire Weekend, The Olms (15)
Jack Johnson, Bahamas (16)
Ludovico Einaudi, Agnes Obel (17)
Thirty Seconds to Mars, The Family Rain (18)
Kendrick Lamar (19)
Primal Scream, Skinny Girl Diet (20)
Haim, Dan Croll (21)
Ellie Goulding (22)
Jessie J, Lawson (23)
Robin Thicke (24)
Pixies, No Ceremony (25)
Tinie Tempah (26)
Dizzee Rascal (27)
John Legend, Robin Thicke (28)
Justin Timberlake (29)