There have been albums released during each of the last six decades that "pushed the envelope," that offered refreshing new ideas and/or innovations to music in general and progressive rock specifically that are not universally acknowledged as "masterpieces" or high and defining achievements of "the genre." I give the following as examples:
In the 1960s The Beatles' Sgt. Pepper's Lonely Hearts Club Band, The Moody Blues' Days of Future Past, and Miles Davis' Bitches Brew are all universally acclaimed for their effect on the course of music (and especially symphonic and jazz-rock fusion) while as albums of songs there is less of a consensus that these are complete and total "masterpieces of progressive rock music." Also, bands like Pink Floyd, The Soft Machine, and The Jimi Hendrix Experience are universally lauded for their innovative contributions to the course of music in the recording (and performance) arenas whereas their albums may not necessarily command that same level of praise or adoration.
In the 1970s, people will extoll the effect that albums like Mahavishnu Orchestra's Inner Mounting Flame, ELP's eponymous debut, or Henry Cow's Leg End were having as well as the effect that artists like Roxy Music, Brian Eno, Kitaro, Kraftwerk, Tangerine Dream, Rick Wakeman, and Klaus Schulze were having on the trends in progressive rock music, but they may be less generous when exclaiming their albums or songs as "masterpieces" of the genre.
In the much maligned 1980s, artists such as King Crimson, Brian Eno, Peter Gabriel, Trevor Horn, David Sylvian, Daniel Denis, and Mark Hollis were integrating many of the new technological advances bursting forth from the computer age into old and new musical forms--creating attention-grabbing landmark or "milestone" albums and songs while not always earning blanket praise and admiration for their risk-taking innovations.
In the computer-keyboard ubiquity of the 1990s many bands were experimenting with trying to blend new and old technologies and styles, employing ambient, classical, chromatic, and minimalist styles like Bark Psychosis and Sigur Rós, Thinking Plague and Meshuggah, and even Cynic and Death, in ways that were being noticed and addressed by journalists and critics but may not have resulted in albums or songs designated with "masterpiece" status.
The Naughties saw synthesis of the heavier elements from the Prog Metal and Tech/Extreme Metal sub-genres into the more traditional by the likes of Tool, Porcupine Tree (In Absentia, Deadwing, and Fear of a Blank Planet), Riverside, Toby Driver, Devin Townsend, and The Mars Volta (and their many imitators) with such seminal yet-devisive albums as Terria, Choirs of the Eye, De-Loused in the Comatorium, Lateralus, and Anno Domini High Definition--all of which are recognized as landmark albums in the evolution of progressive rock music but which do not always receive "masterpiece" acclaim from the entirety of the Prog World.
In the Teens I've seen Bent Knee, District 97, Thank You Scientist, and, most recently, the UK-based black midi express their twist on the future of progressive rock music--all receiving mixed reviews through a plethora of attention.
This new release by black midi is getting a lot of attention. The musicianship is astonishing. The creativity and sense of humor conveyed is on a par with Spanish band Za!, Mr. Bungle, or old Talking Heads and 1980s King Crimson. The composition style is similar, to my ears, to Jem Godfrey and John Mitchell's Frost* productions: quick, compact, concise, packing big punches in a brief amount of time--as if trying to compress a 15-minute epic into a five minute engineering feat. The innovations are commensurate with values and attitudes of Millenials and Gen Z-ers: no fluff, no wasting of time and effort, living every moment for one's own enjoyment, refusing to conform to anyone else's demands or expectations. There are some incredibly refreshing and liberating ideas being expressed through this music. I'm just not sure it's for me--or whether I'm ready to proclaim this album (or it's wonderful predecessor, Schlagenheim) as "masterpieces" of progressive rock music. Maybe we proggers are trying to be too accommodating: bending over backward to welcome any newbies with a fresh idea into the prog realm when, in fact, perhaps we should let them fly free--acknowledge that they're creating something new--something that really goes beyond the planet we like to think of as Prog World. Give them their due: they want to be free, they want to break the chains that have bound us for 60 years--to express their own unique identities. I say we let them. (Do we really have a choice?) perhaps bands like Consider the Source, Fly Pan Am, Fuzz Puddle, PinioL, The Mercury Tree, Monobody, and Unaka Prong are trying to break out, to break away, get out from under the Prog and "classic" or "post punk" rock umbrellas but we won't let them! They've all released albums that are declarations of new directions--"milestones"--but may not receive the love and accolades from the Prog Rock old guard due to their crossing over into other non-prog-traditional stylistic choices, but, who knows! Maybe this is where prog is going! Let the young have their time in the sun!