Music – like all performed arts – relies on an unspoken contract between performer and audience that pretends everything is happening spontaneously. In the theatre we have to be persuaded that the words being spoken are a character’s immediate response to on-stage events, even though we know that the words were written down by a playwright, committed to memory by the actor during a process of rehearsal and spoken more or less the same way every evening. Nonetheless as an audience we are complicit participants in the myth; the actors in a play, for example, do not deny that they rehearse and we in the audience do not claim to be there by accident.
The theatre of a musical concert is also charged with suggestions of the spontaneous: the pianist who sits alone at a piano and starts to play, apparently prompted only by a sudden thought, or – even more magically – the conductor who looks up and with a wave of his arms conjures music into being.
But classical musicians walk a tightrope; audiences and critics alike are unhappy if performers get notes wrong – but castigate them if their reading is too predictable. But where Baroque continuo and classical concertos require improvisation, modern composers have become ever more precise – even tyrannical – about everything in their scores.
Some composers, though, manage to compose this spontaneity into the music. Andriessen and Schönberger wrote of Stravinsky that ‘even though the musical thought is fixed and every performance will sound more or less the same, the thought itself can nonetheless give the impression of being improvised – as if arising out of the playing itself.’
What is it that gives this quality to the music? There are some delightful answers – and games with those answers – in Piers Hellawell’s Cors de Chasse, a double-concerto for trumpet, trombone and orchestra from 2004.
Improvisation, or quasi-improvisation, is unpredictable, asymmetric, quixotic, rich in diversions and dead-ends, liberal, pragmatic, imaginative and unsystematic. Hellawell’s piece has all these attributes and more. There are nods to bebop jazz, specifically in jagged, lightning-fast figuration, piercing rips and flickering licks, and ornamentation of slower melodic lines. The music often feels like it doesn’t know where it’s going, but is enjoying the ride. The wealth of invention carries the music forward.
Hellawell’s twist is to have two instruments share in the improvisation. The tension in the myth of spontaneity is stretched by having two instruments improvise together in duet. The soloists’ first entry is a hectic hocket; at other times they pass a single melodic line, alternating freely. At other times there is a Stravinskian ‘heterophony gone wrong’ – the lines shadowing each other, diverging occasionally. But the most exhilarating moments are when the trumpet and trombone double each other exactly, matching each other phrase for phrase, flourish for flourish, like synchronised tightrope-walkers throwing hand-stands in perfect co-ordination – and with extra marks for style (Ex.1).
Improvisation is provisional, notating music is definitive. The two are apparently incompatible. It feels wrong, locking the precious freedom of an improvisation into notes in black-and-white, like caging a tiger in a zoo. But when it works it is magical, giving you that ‘just-picked’ freshness out of a tin. It is so difficult to do: sitting down, carefully working out music to sound carefree but not careless, painstakingly crafted to sound anything but. Schubert could do it. Mendelssohn could do it. Stravinsky specialised in it. And in Cors de Chasse, Piers Hellawell, gives voice to an improvisation at once glorious and gleaming, restless and resplendent, ingenious but nonchalant, impossible but irresistible.