Rock and Pop Bands and Artists after 1970 who were not truly “prog” (as that term is generally and broadly defined, even by the site), but who were clearly not “mainstream” or simply “rock” bands.

A wide subgenre that encompasses two kinds of bands/artist, that either consist of progressive artist that strayed away from their progressive roots into mainstream rock or were influenced by progressive rock.

Even though the music by these artists is sometimes unrelated it had things in common with prog music in that it was very structured and even adventurous, sometimes hard or heavy, sometimes mellow, strong melodies, good hooks are an integral part of most of the material. Sometimes these artists pioneered other rock genres.

Though most of these artist can't really be considered progressive themselves, their relation to progressive music is not to be underestimated.

Rock-in-Opposition — Often abbreviated RIO, this form of progressive rock relies heavily on early 20th century avant-garde classical structures. Dominated by dissonant chords, odd time meters, polyrhythms, and abstract, sometimes politically-oriented vocals, this style is often dismissed even by die-hard progressive fans. Like the other more avant-garde styles such as Krautrock, it should be listened to, and not just heard. Musicianship is extremely high, yet appreciation is somewhat low. This form of prog is best appreciated in live concert settings as the interaction between musicians is quite astounding to watch.

Avant-Prog - Avant-Prog is short for avant-garde progressive rock. This style appeared in the late 1970s as the extension of two separate prog rock sub-styles: Rock in Opposition (RIO) and prog of the Canterbury scene. RIO is a term restricted to temporal limits; Canterbury prog to geographical limits. The late 1970s onward saw the development of an avant-prog scene often functioning in the margin of mainstream prog. A host of groups and artists mainly from the USA, but also from Europe and Japan, started to write mostly short instrumental pieces that focused on complexity and stripped down instrumentation, while avoiding the pomposity and stage props of the big prog acts