The record has the singing of Horace Andy plus invited vocalists : Tunde Adebimpe of TV On The Radio , Damon Albarn of Blur and Gorillaz , Hope Sandoval of Hope Sandoval And The Warm Inventions and Mazzy Star , Guy Garvey of Elbow and Martina Topley-Bird , as well as guitar playing by Adrian Utley of Portishead ( on `` Saturday Come Slow '' ) , keys from Portishead collaborator John Baggott ( most notably on `` Atlas Air '' ) , keys and synth bass from Damon Albarn ( `` Splitting the Atom '' and `` Flat of the Blade '' respectively ) , guitar ( various tracks ) and bass ( `` Girl I Love You '' ) by Neil Davidge and bass by Billy Fuller of Beak ) on various tracks . The record features the singing of Horace Andy plus invited vocalists : Tunde Adebimpe of TV On The Radio , Damon Albarn of Blur and Gorillaz , Hope Sandoval of Hope Sandoval And The Warm Inventions and Mazzy Star , Guy Garvey of Elbow and Martina Topley-Bird , as well as guitar playing by Adrian Utley of Portishead ( on `` Saturday Come Slow '' ) , keys from Portishead collaborator John Baggott ( most notably on `` Atlas Air '' ) , keys and synth bass from Damon Albarn ( `` Splitting the Atom '' and `` Flat of the Blade '' respectively ) , guitar ( various tracks ) and bass ( `` Girl I Love You '' ) by Neil Davidge and bass by Billy Fuller of Beak ) on various tracks .