California native Robert Rich is a crucial figure in the development of several forms of experimental electronic and ambient music, from ethno-fusion and environmental to dark ambient and space music. He began performing all-night sleep concerts in the early 1980s, and has since performed in a multitude of unconventional spaces, including caves, cathedrals, and galleries. His work reached a wider audience with the 1989 release of Rainforest, which combined natural sounds with electronic drones and exotic instrumentation, set apart by Rich's use of just intonation. He released several well-received collaborations during the '90s, including two albums with Steve Roach and the 1995 dark ambient classic Stalker (with B. Lustmord), in addition to warm, organic solo efforts like the Arabic-inspired Seven Veils (1998). His 21st century work has ranged from the "lost ritual music" of the acoustic Temple of the Invisible (2003) to the richly textured kinetic electronics of Filaments (2015). He is also a scholar of just intonation, writing regularly on the topic and co-authoring the software program JICalc.

Rich began experimenting with electronics in the mid-'70s -- he started building analog synthesizers when he was 13 years old -- before attending Stanford University, where he completed a degree in psychology. While at Stanford, Rich's involvement in the university's prestigious Center for Computer Research in Music and Acoustics expanded his interest in electronic composition, as well as bringing him in contact with a wide range of nontraditional, non-Western musical ideas. Rich's performance of several all-night sleep concerts during this period also helped solidify an aesthetic focus on psycho-acoustics, perceptible in early recordings such as Trances (1984) and Numena (1987).

Rich's profile was raised considerably when Rainforest was released by Hearts of Space in 1989. Much more mature and cleaner-sounding than his earlier material, his work combined electro-acoustical elements (Rich plays a wide range of instruments, from synths and effects racks to hand drums and flute) with an increasing interest in digital sound manipulation. Inspired by the more textural works of artists like SPK and Throbbing Gristle, Rich's interest in the edgier side of electronic composition also earned him a reputation among fans of gothic, industrial, and dark ambient, hinted at with his Steve Roach collaborations (1990's Strata and 1992's Soma) and made most obvious by the 1995 cult favorite Stalker, with Brian Williams of Lustmord. Fissures, a 1997 collaboration with Alio Die, was a fluid blend of acoustic instruments and haunting drones, and 1998 solo release Seven Veils explored Middle Eastern influences.

By this time, Rich had become a well-respected sound designer, developing presets for synthesizers and sound modules, as well as working on Hollywood films. He also developed loops for Sonic Foundry's ACID music software. Live triple-album Humidity: Three Concerts was released through Rich's own Soundscape label in 2000, and Bestiary appeared on Release Entertainment in 2001. During the same year, Rich released the seven-hour audio-DVD Somnium, a re-creation of one of the aforementioned sleep concerts from the 1980s (he had revived the format in 1996). Outpost, with Ian Boddy, was released by DiN in 2002. The acoustic Temple of the Invisible, recorded with several guest musicians and incorporating a variety of North African, Asian, and European traditions, appeared in 2003. In 2004, Rich released Calling Down the Sky, a dark drone album recorded live in Denver, and Open Window, comprising improvised piano solos.

Rich remained productive, issuing solo works like 2006's pulsating Electric Ladder, a film score (2007's Atlas Dei), and further collaborations with Boddy as well as Markus Reuter and Faryus. After the release of a live archival series in 2009, Rich continued to issue studio albums, including 2010's Ylang and 2012's well-received ambient work Nest. Perpetual, a continuation of Somnium, was released as a Blu-ray Audio disc in 2014. The Berlin School-influenced Filaments appeared in 2015. The darker Vestiges and more tribal What We Left Behind both saw release in 2016. In 2017, Rich issued Live at the Gatherings 2015 and Lift a Feather to the Flood, his second collaboration with Markus Reuter. Solo full-length The Biode was released in 2018, and double album Tactile Ground came out in 2019. ~ Sean Cooper & Paul Simpson, Rovi