Following playing a storming Other Stage headline set at last weekend's Glastonbury with Portishead, the group's Adrian Utley has announced that he'll be putting out a solo release via bandmate Geoff Barrow's Invada label.

Adrian Utley’s Guitar Orchestra's In C, out on September 30, is a recording of a performance of Terry Riley's landmark 1964 minimalist piece Utley did earlier this year at Bristol's St. George's Hall with 19 guitarists, along with four organs and a bass clarinet. Taking part in the show were Portishead's live guitarist Jim Barr, PJ Harvey collaborator John Parish and label mates Thought Forms, and we've got a first look at a newly-edited clip of the show - have a watch above.

Says Utley: “I've been exploring the sonic possibilities of massed guitars for a while now in various contexts from pure noise to the sacred choral music of Arvo Part. So it was interesting to see what would happen if we had 19 electric guitars plus organs playing ‘In C’. It is an amazing piece of writing and original thought. A new free idea of organised group playing. The beginnings of what we know as minimalism."

Utley will be performing the piece with some of the original musicians alongside local guests in England, France and Poland later in the year - stay tuned to the Quietus for updates on the dates, and have a watch of Portishead's Glastonbury performance of 'We Carry On', courtesy of the BBC, below: