M is the one-letter musical pseudonym of Robin Scott. Initally a record producer (though he did put out one album under his real name in 1969, which ended up going nowhere and is very rare today), he put together a dance band in the late 1970s. He had a couple of minor UK hits with "Moonlight and Muzak" and "That's The Way The Money Goes", but his biggest hit was "Pop Muzik".
The M records were typically critical of the government and basically the Conspiracy – I'm not sure if he was ever a SubGenius, but if not, he would have fit in alongside DEVO, thematically. Frequently, there's a paranoia about his lyrics, along with some anger, as well, but the anger usually found itself sublimated as deep sarcasm. His later records didn't do very well, partially because of the dark nature of what was on the surface, dance pop; his third (and last) album was only released in France, and his Jive Shikisha! album wasn't released at all until 1998, despite being recorded for a 1984/1985 release.