Short answers, pulled from the story.
The term industrial music was coined in 1976 by artist Monte Cazazza as Industrial Music for Industrial People. This phrase served as the strapline for the record label Industrial Records founded by Throbbing Gristle.
Throbbing Gristle was formed in Yorkshire in 1976 as the musical offshoot of the Kingston upon Hull-based COUM Transmissions. The group was composed of Genesis P-Orridge and Cosey Fanni Tutti, with Peter Christopherson joining in 1974 and Chris Carter following in 1975.
Italian Futurist Luigi Russolo laid the groundwork with his 1913 manifesto The Art of Noises and his assistant Ugo Piatti created Intonarumori noise machines. Other influential figures included Arseny Avraamov, Arthur Honegger, George Antheil, and John Cage who expanded the concept of found sounds.
Nine Inch Nails and Marilyn Manson achieved commercial success during the 1990s with albums certified platinum by the Recording Industry Association of America. Nine Inch Nails released Broken in 1992, The Downward Spiral in 1994, and The Fragile in 1999, while Marilyn Manson released Antichrist Superstar in 1996 and Mechanical Animals in 1998.
Throbbing Gristle declared industrial to be anti-music and opposed traditional rock music structures associated with the punk rock scene. The group used homemade instruments such as Chris Carter's Gristle-izer, which consisted of a one-octave keyboard and cassette machines triggering various pre-recorded sounds.
Post-industrial music offered more accessible and diverse styles with the incorporation of traditional pop songwriting and influences from genres including new wave, rock, pop, heavy metal, hip hop, jazz, disco, reggae, ambient music, folk music, post-punk, EDM, and new age music. This splintering occurred as the genre evolved from the avant-garde experiments of the 1970s to the platinum-selling records of the 1990s.