Cantus was composed for Carla Rees and was premiered by rarescale as part of their 10th anniversary season in 2013. It consists of a free melody based on a scale comprising intervals derived from the first, third, seventh, eleventh and thirteenth tones of the harmonic series. It may be performed as a solo or with accompanying drones.
"Cantus" has a number of meanings in music terminology; the primary meaning I have in mind here is the simplest one, of a melody. There are various variants, but the one that comes closest to what I have in mind in this piece is Cantus simplex planus, which Grove defines as "a simple melody using notes of indefinite value, as in Gregorian chant." There is something chant- or prayer-like about this melody, though as I am a confirmed atheist, I can't say to whom the prayer might be directed.