Light speed with time canons

Written to mark the centenary of Arthur Eddington’s experimental proof of Einstein’s Theory of General Relativity, this piece was premiered by the BBC Philharmonic Orchestra in Salford, November 2019 (live broadcast on BBC Radio 3: https://www.bbc.co.uk/programmes/m000b0mj).

The principal research aim was to find a musical analogue for the Theory of General Relativity, referring specifically to the phenomenon of time dilation, through which our perception of the passage of time differs for objects moving at different speeds relative to the Speed of Light, a universal constant. The research developed three methodologies:
1.The Speed of Light was represented through developing cantus firmus (CF) technique so that – whereas conventionally it is the slowest-moving voice – the CF is made the fastest part, becoming a moto perpetuo, while retaining its function as a durational constant underpinning parts whose tempi shift around it. As the harmonic rhythm is slowed, the listener’s perception of the music’s pacing alters, causing the CF to shift from foreground to background. This technique was informed by Obrecht’s use of a contrasting CF mensuration in his mass Ave Regina Caelorum (described in Wegman, Born for the Muses, 1994), and by changes of pace achieved through reinterpreting unchanging material in Sibelius’s seventh symphony and Berio’s Points on the Curve to Find…, the innovation here being that such shifts are the focal point of the piece.
2.Mensuration canons were employed to create transitions of musical pace in the parts surrounding the cantus firmus, informed by study of such devices by Ockeghem, Bach, Messaien and specifically Nancarrow, in whose Player Piano Studies the entry of the faster voice after the slower results in an increase in energy as the pace accelerates; here the process is reversed, generating a deceleration effect that shifts the listeners’ perception of the canonic material from melodic to harmonic, thus inverting the relationship between the canons and the cantus firmus.
3.The use of the pivot tone to bring about harmonic shifts by reinterpreting a given tone relative to changing tonal foundations – outlined within nineteenth-century common-tone harmonic theories – was applied to spectral theory (especially methods used in Tenney’s Arbor Vitae and Lindberg’s Joy): pitch structures used aggregates of tones selected from the notes of the harmonic series for particular fundamentals, but, because they manifest as different partials over several fundamentals, they are open to reinterpretation, so the listener’s ear is tricked into perceiving a complex aggregate of notes as a different set of overtones.

The research provided insights into some of the ways in which rhythmic analogues and proportion can be used to replace processes originally formulated in terms of pitch, and in particular how large-scale structure can be articulated through rhythmic processes in post-tonal music, as well as new ways of achieving harmonic shifts between spectral complexes.