All three works on this disc are essential Birtwistle. Oliver Knussen is one of best conductors in the world. The London Sinfonietta needs no introduction. And NMC is one of the great independent labels. What else do you need?
Well, I know Birtwistle's music alienates some people, and in its way it is more radical than anything 50/60s Darmstadt serialism could offer. But it is perhaps also the most interesting, often in a extra-musical way.