A pretty decent argument can be mounted that progressive rock — or “prog” as we know it today — was born with the 1969 release of King Crimson’s first album, In The Court Of The Crimson King.
The band’s early fans included Pete Townshend and Jimi Hendrix, and it only took one listen for legendary music-exec Ahmet Ertegun to sign them to his Atlantic Records on the spot.
In The Court Of The Crimson King made its impact way back in 1969, by breaking the blues-rock mold of British rock at the time. The original album has only five tracks, and there is not a guitar solo amongst them (even though Crimson’s Robert Fripp was and remains one of rock’s most inventive guitarists).
Prog-rock bands from Genesis to Rush to Porcupine Tree (whose Steven Wilson is overseeing King Crimson’s remastered albums) all adopted Crimson’s blueprint in one form or another over the decades to come.
Interestingly the original King Crimson lineup only produced this one album, and broke up later that same year. Fripp would however keep the name and front several subsequent lineups — featuring at one time or another great musicians like Greg Lake, John Wetton, Adrian Belew, and Bill Bruford — for decades to come. You’ll find bloggers talking about King Crimson at sites like Krimson News.