This is a topic that i spend alot of sleeples nights thinking about Progrock defnitions and what are the major parts that differ prog rock to art rock as genres.
first of I will explain may theses on Progressive Rock
Progressive Rock as an adjektive, is rock that are moving from one standing place to a complete different state, their is an equvelent to the movement of progressivisme politics in th early 1910-20 in th US, about progressing the wellfare, economicy, household, etc. to rapidly move a nation from one step to a new era.
the same can be said about the music before and after the 60s/70s, from what I know thier was no movement which pushed or filtered so many influence through one spcial apraoch as the Psychadelic rock bands later Progressive rock bands did to the rock'n'roll, british invaision and Appache bands (the Shadows influenced movement). to my shallow impression their were before the 60s stricter bounderies between the styles, it was Blues (with its warriations), Jazz (with its different aproaches, be-bop, swing, ballads), Country (bluegrass,Southern rock, Celtic rock the Pougues), Rythem and Blues, Funk, Soul, 20th Century classical music (Gershwin), Raggtime, Vaudeville and music scores. the thing that the English Porg bands did was, the former genres are mostly American based genres or was expressed there, the English bands wanted to play those gernres but they had different accents, history, approach and other musical roots like European Classical music (with all its periods), gregorian chants, Folk, medeval or trubadour traddisjon (people playing lut/other string instruments, flute, accordieon and drum), church music, hymns, opera, and dramatical plays.
the way I see Progressive
Rock as somthing different then Art
Rock is the way the rock genre is apraoched the classic prog bands as we all know are besett by Virtuoses (exept Pink Floyd), and they wanted to play rock n roll but since they was so good musicians and could filter trhough them influences from other sources then plain rock, the firts rock bands of the 60s who played a mixture of rock'n'roll with rythem and Blues, with its outspring from Country music, but with a British tone, the American rock bands like the Beach Boys, Mamas and the Papas, the Byrds and Everly Brothers took hughley influence from rock but it was also hints of Tin Pan Alley or Irving Berlin, with more melodic, and harmonique aproach. but while the 60s went on (im born in the 80s so this is just my perspective as a noooob

) alot of expression was
filterd through the rock bands like
procul harum, moody blues, the Beatles, pink floyd, Soft Machine, traffic, the Nice, and others they took a 3 gallons of rock, then some gallons of psychadelia, some spoons with jazz, folk, classical, medeval, folklore, fantasy, drug etc + virtuosic skills on instruments or mindesett (Pink Floyd), to expand, evolve, revolutionise the face of rock from 1970 until 74 / 75 with bands like
genesis, yes, gentle giant, camel, EL&P, KC, VDGG, Magma, Gong, MO, Rush and Kansas (futher from 74 until 77) which I will call the perod wenn Progressive rock/music was at its freshest, a SPARK of imagination, creativaty, individuality and conceptuality was in full blossum, the Prog Rock bands took bigger leaps then the Art Rock bands (which I will describe futher down), the instrumentation was fuller, use of different instruments was more prefound, more clearer notch to Academic music such as Jazz and Klassikal music, more eatherial, crazy'er concepts, stronger individuals.less love related songs, composition as more important then songwriting (exept
Genesis and
Kansas were i think the music and lyrics are equaly important)
Pink Floyd is the odd cow out of these bands they are stylisticly closer to the
Art Rock bands in style and as a band, but their history and placement in time line placehem as a Progressive rock band also.
Art Rock (a sister genre) when i think of
art rock as a genre I see it as a more song related genre instead of composition, more focus on the hole pacage as singer/songwriting, less virtusic (but still better then most), bands i regard as the pure art rock bands are
Pink Floyd, Electric Light Orcestra, Roxy Music, Supertramp, 10CC, Alan Parons Project, Queen, Wishbone Ash, Sparks, David Bowie, these bands are progressive but not as ambitious as the
prog bands i see this bands use alot of inspiration from film music, music from stage (theatre, vaudeville, opera, oprette, musical, cabarette, dramatical, circus) wtih rock, but also strong hints of Jazz, Classical, pop,
they are lighter bands conceptly, I genraly feel the songwritng is better in Art Rock but the composed music is stronger in Progressive rock it chalange you more, wile Art Rock is i feel more focused and tight, but it is led place to free artistical expression. (which makes it more challenging the Soul, Disco, funk and Garage rock
so what do you think and if you would like to express other opinions or a different viewpoints you are welcome to join in you are allowed to disagree or outdeep the subject
my question is there a difference between Art and Prog Rock (stone, rubble)