EXAUDI is one of the world’s leading vocal ensembles for new music. Founded by James Weeks (director) and Juliet Fraser (soprano) in 2002, EXAUDI is based in London and draws its singers from among the UK’s brightest vocal talents. EXAUDI’s special affinity is for the radical edges of contemporary music, at home equally with complexity, microtonality and experimental aesthetics. The newest new music is at the heart of its repertoire, and it has given national and world premières of many of today’s leading composers.

The Mirror of Speculation

Between the years 1370 and 1420, a style of composition flourished in Europe of unprecedented brilliance, complexity and strangeness. Composers around the courts of Northern Italy and Southern France delighted in exploring the limits of musical possibility – rhythmic, harmonic, polyphonic – experimenting with dizzying arithmetical forms and bizarre notations: music written in the shape of a harp, or a heart, or in concentric circles in different colours of ink. This age has been dubbed the Ars Subtilior, or Subtler Art, in which the innovations of the 14th-century Ars Nova were raised to new heights of beauty and expressiveness through a process of musical speculation.

The medieval act of speculation – intelligent contemplation or close observation (as opposed to the modern sense of conjecture) – is central to the Ars Subtilior, and connects it strongly to the music of the present day. In our own time, many composers have been fascinated this remarkable music, as well as by Guillaume de Machaut, the composer-poet whose astonishing achievements foreshadowed Ars Subtilior’s innovations.

In this programme, EXAUDI create an aula specularum – a Hall of Mirrors – reflecting ancient and modern speculations back on each other until medieval and contemporary seem to merge. From the Ars subtilior repertoire, Ciconia’s puzzle-canon Le ray au soleyl is ‘solved’ in a multitude of ways; Senleches’ famous La harpe de mellodie is performed both with and without its canonic triplum; and Rodericus’ notoriously hermetic Angelorum psalat is presented in competing notations and turned into a musical uroboros, eating its own tail. Machaut’s lilting lovesongs are interleaved with Evan Johnson’s delicate treatment of Petrarch, and then filtered through a work by John Cage in James Weeks’ Four Virelais.

At the heart of the programme is the world premiere of a brand new work, speculative in every sense, by the composer Mark Dyer. Dyer trained a computer to ‘learn’ the notation of the English Old Hall manuscript, dating from c.1415, using machine learning, and to produce new facsimiles, which Dyer transcribed. The resulting compositions are attributed to a fictional 14th-century musician and presented alongside original Old Hall works in a fascinating extension (and obfuscation) of ‘speculation’ – this time by an incognito, non-human composer. The programme is introduced by director James Weeks, and presented in an approachable and engaging way that balances the educational with the entertaining.