Crepitum (2010) by Mauricio Rodriguez
for viola
World premiere; Earplay/SF Foundation commission

Crepitum (Latin for "to rattle") is a piece that explores the dual concepts of harmonicity and non-harmonicity (terms after the theoretical proposals by composer Clarence Barlow.) The music of Crepitum is based on a harmonic sequence where the consonance/dissonance of each chord is modeled through the observation of a typical sensorial phenomenon, from which simple integer frequency ratios are easily relatable to intervallic relationships perceived as 'smooth' or 'terse.' These proportional ratios are also used to define the length of each section and the rhythmical patterns of the piece, therefore, extrapolating the harmonicity of a chord to a specific metricity (or non-metricity.) When harmonicity/metricity are highly unstable (rather inharmonic and nonmetric) the harmonic progression either starts a new process or extinguishes the overall musical flow.