In 1989, when the English rock band King Crimson released a so-called “Definitive Edition” of its 1971 album, “Islands,” a hidden track that closed the original LP was omitted through an engineer’s error. The change was slight, but a hue and cry went up among faithful fans of the trailblazing prog-rock institution. On subsequent reissues, the cut — a snippet of studio ambience, violins tuning, and a countdown by Robert Fripp, the band’s guitarist and perennial architect — was duly restored.  For King Crimson, whose name was coined as an analog for Beelzebub, the devil’s always been in the details. Fripp, famously press-averse, might have been making precisely that point last Tuesday at the Egg in Albany, N.Y., when that sly morsel from “Islands” burbled through the P.A., counting in the public coronation of a new King Crimson.  Spanning the front of the stage were three drummers — Pat Mastelotto, Bill Rieflin, and Gavin Harrison — natty in their matching charcoal formalwear. Similarly attired on a riser behind them were Fripp, saxophonist Mel Collins, bassist Tony Levin, and singer/guitarist Jakko Jakszyk. The first band to tour under the King Crimson name since 2008, the unorthodox septet plays the Colonial Theatre on Monday and Tuesday.  Speaking in a dressing room before the debut show, Rieflin asserted that conceptualizing Fripp’s unlikely new configuration had been easy; enacting it, considerably harder.  “You think, wow, that’s a great idea: The possibilities are endless,” he said. “But once you begin to move from possibility to actuality, that’s the difficult part.” The drummers, he related, had rehearsed together for months before joining the rest of the group: “We sat in a room with our equipment, looked at each other, and said, well, how are we going to make this happen?”  Onstage, they shifted between choreographed thunder and diplomatic deference. Mastelotto, a new kid in 1995’s double-trio Crimson, qualifies for veteran status; Harrison, the drummer for the popular neo-prog group Porcupine Tree, came aboard for the fleeting 2008 revival. Rieflin, known for his work with R.E.M., Swans, and Ministry, is a Crimson neophyte. But he enlisted Fripp for two 1999 CDs and has worked with him in various settings since.  The remaining players span still more of King Crimson’s chameleonic legacy. Levin, part of an early-’80s Crimson steeped in new wave, gamelan, and classical minimalism, is now on his fourth tour of duty. Collins, a session star whose playing has enlivened hits like the Rolling Stones’ “Miss You” and Wang Chung’s “Dance Hall Days,” last toured the States as a Crimson member in 1972, part of a volatile quartet known for bluesy jams and vicious rows.  With Jakszyk, a respected singer, songwriter, and guitarist formerly of the English band Level 42, and other fellow alumni, Collins had revived early Crimson material as 21st Century Schizoid Band, which ran from 2002 to 2004. In 2011, Collins and Jakszyk recorded a set of new songs with Fripp, who declared the resulting album, “A Scarcity of Miracles” (completed with Levin and Harrison), a “King Crimson ProjeKct” — his term for satellites spun off from the main group.  “Robert was keen to get the band together again then,” Collins said by telephone from Philadelphia a few days after the Albany premiere. “And at the last minute, Robert decided he didn’t want to do it, he didn’t want to go back on the road.” Collins laughed. “My history with King Crimson, right back in the early days — it was on, it was off,” he continued. “I spent about two years before we actually got a band together.”  But within a few years, Fripp had resolved legal battles that had prevented him from embracing new ventures. Time, as the saying goes, healed whatever wounds remained.  “Things have changed, people have mellowed over the years,” said Collins, who’d just spent 18 years in Germany, playing in a talk show’s house band. “I always respected Robert anyway. I just put that all to bed, the King Crimson that I was in; this was a great opportunity, and the right time for me.”  Time, too, for songs that had not figured into a Crimson set list in more than 40 years — which is not to say that Fripp set out to play all the “hits,” so to speak. In a rare interview with Uncut magazine, he cautioned would-be audience members: “If you go there thinking, ‘If I don’t hear “In the Court of the Crimson King” I will have a lousy show,’ then you will have a lousy show.”  Still, the new group encompasses a broader range of Crimson canon than any previous lineup. The set ranges from 1969 to 2011, alighting at nearly all points in between, incorporating new bits, and even fusing sounds from disparate eras. In Albany, “21st Century Schizoid Man” was treated to a sleek rhythmic overhaul. A 1994 double-trio piece gained a burping baritone-sax line, while an electronic-bells interlude from 2002 was adapted to preface a roiling 1971 instrumental.  “I think everyone had their own ideas about what would be fun to play, what they’d like to hear, what an audience might like to hear,” Rieflin explained. “Our repertoire is taken from the scope of the band’s history. However, the approach that we’re taking for ourselves, as players, is that all of the music is new, regardless of when it was written.”
Touring with a characteristically unorthodox new lineup of King Crimson that comes to Boston on Monday and Tuesday, Robert Fripp is revisiting songs he hasn’t performed in decades.