Scottish rockers Biffy Clyro performing earlier this year at Glastonbury
Biffy Clyro and Adele have been added to the line-up for Mencap's Little Noise sessions in London.
Both acts will be headlining two dates for the 10 day charity event at the Union Chapel.
Reverend and The Makers, White Lies, Friendly Fires, Katy Perry, Frank Turner, General Fiasco, Fight Like Apes and The Hours have also been added to the bill.
The intimate shows will be held from 8-18 November.
They join Kasabian, Razorlight, Stereophonics, Glasvegas, Keane, James Morrison and The Fratellis for this year's line up.
Little Noise Sessions
Glasvegas, White Lies, Cage the Elephant (8 November)
Razorlight, Florence and the Machine, Esser (9)
Stereophonics, Seasick Steve, General Fiasco (10)
Adele, Angus & Julia Stone (11)
Biffy Clyro, Friendly Fires, Frank Turner (12)
James Morrison, Katy Perry, Sam Beeton (13)
Kasabian, Reverend And The Makers, The Hours, Fight Like Apes (14)
Keane, The Script, Bryn Christopher, Red Light Company (15)
The Fratellis, Sergeant (18)
Newcomers Cage The Elephant, Florence And The Machine, Red Light Company, Esser and Bryn Christopher are also performing at the acoustic gigs.
This is the third year the Little Noise Sessions have been held.
In the past, Amy Winehouse, Noel Gallagher, Snow Patrol, Duffy and Lily Allen have performed at the event.
As with previous sessions, which saw impromptu appearances from U2 and Coldplay, a number of surprise guests will also be performing this year.
Tickets are available from Mencap's official site.