California born guitarist Stephan Thelan, the principle composer of the group, is the practitioner of a democratic process of creation and participation. A PhD in mathematics with extensive classical training, Thelan studied with guitarist Robert Fripp. Fripp, one of the most influential artists in progressive music history, and a founding (and ubiquitous) member of King Crimson, had a significant impact on Thelan and the halo effect of King Crimson's shadowy intensity looms large on Black Light.

Guitarist Bernhard Wagner, a software developer as well as musician, combines those skills in evolving repeated melodies and rhythmic patterns. Wagner has worked as a backup act for Nik Bärtsch's Ronin for many years. Bassist Christian Kunter has strong ties to free jazz including having played with two of John Tchicai's groups. Drummer Manuel Pasquinelli has played in numerous regional bands covering an eclectic mix of styles from punk to chamber. The unique sound of SONAR is due, in large part, to the tritone tuning (C / F# / C / F# / C / F#) of the guitars and bass adding a surprisingly pleasant dissonant quality.