London four-piece Hejira's debut album Prayer Before Birth, set for release imminently through Accidental Records and produced by none other than label head Matthew Herbert, will get launched with a one-off show at The Clapton Round Chapel in Hackney on October 31, accompanied by an 18-piece vocal and instrumental ensemble.

Ahead of that, the band are releasing a single, 'Litmus Test', next Monday, September 16, and we've got an exclusive first spin of the remix by Seb Rochford, the hyper-prolific drummer and founder of Polar Bear, Acoustic Land and many other groups, which features UK MC Jehst (it joins another remix by Floating Points on the 12"/digital release). It's a fearsome reworking, setting up two distinct halves: the first is built out of whispered, reversed sounds, punctuated once by a jarring, seismic shard of noise, recalling Herbert's recent The End Of Silence work, before Rochford works up a juddering beat to usher in Jehst for the second.

Have a listen below, and head to the band's website to get hold of tickets for the album launch: