It would be a lie to say that I understand most of the music on this disc. All one can do with music as esoteric as this is to remember the greatness of what Birtwistle has written before and go on listening. The best way to approach it is to take the central item, called Bogenstrich – Meditations on a poem of Rilke and work outwards from there. It consists of a very beautiful love poem, sung twice in different versions. The first is with piano accompaniment, played by the excellent Till Fellner, and then, after three lovely instrumental meditations, with the cello accompaniment of Adrian Brendel. The singer of what sounds like an extraordinarily difficult vocal line is Roderick Williams, always a great artist and here setting a standard it is hard to imagine being equalled. The other vocal items are to poems by the American modernist Lorine Niedecker, whom I find wholly unintelligible, with music to match; and the soprano Amy Freston evidently found it hard to articulate the words. The single-movement piano, violin and cello trio also needs many more hearings than I have so far been able to give it. But I take it that the performances are definitive, they certainly sound confident.