CONSTRUCTION 004: IMPLIED RHYTHMS
Performed at the Guildhall School of Music and Drama: March 2019
Implied Rhythms is written for 16 loudspeakers and lasts 5 minutes. In response to the signal/noise theme of the brief, Implied Rhythms finds musical content within the wave phenomenon of beat frequencies – where a series of beats are perceived as a result of interference between two or more similar (but not identical) acoustic tones. The beat effect is highly spatial, as it only occurs when the tones are sharing the same air. Beats are not perceived if two close tones are played through headphones and assigned to opposite ears, however the effect can be simulated with a mono mixdown (linked to at the bottom of this page). The 16 loudspeakers are grouped into 8 pairs, labelled as A and B in the diagrams below. The sinusoidal tones played on the A loudspeakers are shifted a small pitch away from those played on the B loudspeakers. The tones which are 2Hz apart articulate a crotchet rhythm. In relation to this, the tones at 0.5 Hz apart describe semibreves, then tones at 1Hz apart are heard as minims and the oscillations at 3Hz apart as crotchet triplets.