Sum Of R is a project of Reto Mäder (Ural Umbo, RM74), formed in 2007 to create slow moving episodes of hypnotic and perplexing music led by a psychedelic understanding of minimal soundforms.

Current members:
Reto Mäder - bass guitar, drones, synth, effects (2007-present)
Jukka Rämänen - drums, percussion, sounds (2019-present)
Marko Neuman - vocals, synth, noise (2019-present)

(Some of) Former members:
Christoph Hess (2008-2011)
Roger Ziegler (2008-2011)
Julia Valentina Wolf (2012-2013)
Isabelle Ryser (2014-?)