King Crimson play June 12–13 at the Moore Theatre. TONY LEVIN

Years Active: 49 (with periodic breaks).

Provenance: London, England.

Essential Albums: In the Court of the Crimson King, Lizard, Earthbound, Larks' Tongues in Aspic, Starless and Bible Black, Red.

Essential Songs: "21st Century Schizoid Man," "The Court of the Crimson King," "I Talk to the Wind," "Cat Food," "Earthbound," "The Battle of Glass Tears," "Red," "The Great Deceiver," "Easy Money," "Fracture," "One More Red Nightmare," "Starless," "Larks' Tongues in Aspic Part I," "Sleepless," "VROOOM VROOOM."

Influenced by: Béla Bartók, John Coltrane, Jimi Hendrix, the Moody Blues, the Beatles, Frank Zappa, Procol Harum.

Influence on: Roxy Music, Henry Cow, Don Caballero, Bitch Magnet, Trans Am, At the Drive-In, the Mars Volta, Neurosis.

Precautions: Robert Fripp will not allow fans to take pictures of, shoot video of, or record any part of a King Crimson live performance. If you have to ask why, you don't know Robert Fripp. Remedy that.

Why You Should Give a Fuck: Let's say you lived in a horrific world in which you could listen to only one English prog-rock group. In such a grim scenario, you should make it King Crimson. Granted, Yes, Genesis, Soft Machine, Emerson, Lake & Palmer, McDonald & Giles, Egg, Gong, Caravan, Gentle Giant, Gnidrolog, and others of their ilk have a lot to offer the adventurous rock listener. But none of these outfits has Robert Fripp in their ranks. A master guitarist and sonic conceptualist on the level of collaborator Brian Eno, Fripp is a once-in-a-half-century musician who has guided King Crimson through many fascinating permutations over almost that length of time.

To state the obvious: King Crimson's 1969 debut LP, In the Court of the Crimson King, is an essential part of every intelligent person's record collection. An ideal marriage of vibrantly pretentious lyrics, origami-intricate composition, and bravura instrumentation, it represents the most resonant example of prog rock—and maybe the earliest. The album opens with the terrifying, lurching metal-jazz of "21st Century Schizoid Man," then slam-cuts into the mellower-than-thou folk reverie "I Talk to the Wind," capturing the most shocking and hilarious moment in this most serious of rock styles. The breathtaking transition from calamity to serenity is unparalleled.

At their peak—from Crimson King to 1974's Red—King Crimson possessed unsurpassable songwriting chops, moving from potent rock-god riffing (see especially "The Great Deceiver" and the aforementioned "Schizoid Man," which Kanye West and other hiphop artists have sampled) to ornately beautiful balladry to mercurial miniaturist improv with unmatched precision. Yet for all their world-class complexity and virtuosity, King Crimson often performed in large venues and shifted substantial units on major labels. To paraphrase a passage from drummer Bill Bruford's autobiography, "King Crimson were the only band in the world who could play in 17/8 time and stay at 5-star hotels."

After a six-year hiatus following 1975's live USA record, Fripp launched a new formation of King Crimson in 1981. They entered a fruitful period during which the band cut a trilogy of LPs—Discipline, Beat, and Three of a Perfect Pair—combining art rock, new wave, disco, and a westernized strain of gamelan. Fripp and Adrian Belew's guitars took on a burnished steeliness while the latter's David Byrne–like bellow polarized many longtime fans (or was it just me?).

Anyway, 1980s-era King Crimson became a different beast, but still magisterial, still complicated, if not as flowery as the flute-/mellotron-enhanced bands of the 1969–1970 phase. Later full-lengths like THRAK and The ConstruKction of Light explore a kind of high-IQ arena metal with which I've never really connected, along with pieces that hint at the ambient grandeur of Fripp and Eno's Evening Star. Whatever you think of these releases, you have to respect Fripp and company's refusal to stagnate in their golden years.

When King Crimson played the Moore Theatre in 2014, I reviewed their performance thus: "[It] is like seeing a Kandinsky painting come to life before your eyes, with their baffling mathematical complexity, grotesquely bombastic beauty, and dramatic shifts in dynamics."

There's no good reason to expect anything less in 2017. recommended