ATP just released a free 2 hour mixtape curated by Portishead to promote next months' I'll Be Your Mirror London festival - featuring Portishead, Grinderman, Godspeed You! Black Emperor, PJ Harvey, Swans, DOOM, Company Flow, The Books, Beach House and Caribou amongst many others. You can get it here:

http://illbeyourmirror.com/mixtape/