you can’t but be stunned by the fearless skill of Sigvards Klava’s choir as they navigate the most jagged, fragmented notes and pitches – the musical equivalent of climbing Mount Everest just with your hands and feet.

The performers are expected to follow certain rules or guidelines, and Cage offers a pronunciation guide, but there’s still considerable freedom in performance and here the choir sounds more assured and committed.

one is unsurprised by the unconventionality but taken aback by the richness and variety of the final musical result. It must be said as well that the singers sound as though they are enjoying themselves enormously.

I can only salute the singers of the Latvian Radio Choir for handling the extraordinarily perilous and challenging closing piece here...Throughout, this remarkable choir never drops a single stitch.