So it was that Birtwistle bookended the evening. The first piece was his Fantasia upon all the notes (2012), commissioned by the present ensemble and premiered at the Wigmore Hall in March 2012. Scored for flute, clarinet, harp (the sound of the harp, although not omnipresent, was a Theseus-thread through the evening) and string quartet, the score breathed out a lyric expansiveness, its long lines fully honoured here and leading to a frenetic climax before the piece effectively disintegrated. The basis for the composition (“all the notes”) is the shifting scales of the harp, dependent on the pedals used. In this way, the harp, by no means soloistic, subtly guides the harmonic language of the piece. It was a fine example of the composer's subtle practices, and was beautifully and sensitively delivered here by members of the Nash Ensemble.
Carter and Birtwistle are of course linked by age as well as the complexities of their music (although the manifestations of those complexities are, of course, very different). There were two Carter pieces in the first half: Enchanted Preludes of 1988 and Esprit Rude/Esprit Doux of some 22 years previous. The first, Enchanted Preludes, is scored for flute and cello, here played by Philippa Davies and Adrian Brendel, respectively. It was a virtuoso performance of a sophisticated piece. Both players demonstrated superb control of their instruments in a piece that demonstrates, concisely, Carter's strengths of a consistent harmonic language and a superb ear for detail. If Esprit Rude/Esprit Doux for flute and clarinet (Davies again, this time with Richard Hosford on clarinet) was not quite as fine a piece, not as sure of itself, it nevertheless evinced a great sense of dialogue.
The Adams was the odd man out. Somehow Shaker Loops, in its chamber version for seven strings, felt rather roughly 'inserted' in deference to the American side of the concert series. It was a fabulous performance: perfectly graduated crescendi and a real sense of determination. But the piece felt over-long and frankly bloated, and was firmly compositionally outgunned by its companion pieces.
Elliott Carter's Mosaic of 2004 (for flute, oboe, clarinet, harp, string trio and double-bass) began the second half. The harp part is virtuosic but in the pre-concert talk Birtwistle had contrasted Carter's treatment of the instrument to his own: Carter does not let the instrument resonate (and therefore, by implication, be true to its own nature). The complex pedal work is impressive indeed as a performance act and one does have to wonder if this aspect is part of the piece's basis, just as the viola is asked to be contra-itself and be very forceful; very un-viola-like perhaps. It is an interesting piece, certainly, but it was overshadowed to no small extent by the piece that most people had surely come to hear, Birtwistle's recent The Moth Requiem (2012).
The BBC Singers were on absolute top form for the demands of this work, which sets a number of Latin names of butterflies interspersed into the poem “A Literalist” by Robin Blaser from his larger work The Moth Poem. The poem concerns a moth trapped in the body of a piano and which could be heard in contact with the strings. It is a lovely idea, and masterfully realised. The scoring is for 12 singers, 3 harps and alto flute. In fact Birtwistle uses the three harps as one “meta-instrument”, as he explained in his characteristically dry-witted pre-performance event. Birtwistle's years of experience enabled him to weave an intoxicating sonic tapestry. The fragmenting of texture and musical material in the work's final stages is impeccably timed. This is nothing short of a masterpiece.
Running through the concert was the sure direction of Nicholas Kok, whose clarity as a conductor was a model of its kind. A remarkable evening.