Both Old and Traditional Knowledge have it that Tangerine Dream were a synthesizer group in the seventies with at least one member wearing headphones in concert at all times because depending on which year in the seventies, it’s generally a true statement. But Tangerine Dream had other not-so-obvious aspects that remained hidden for years, helped along by tactics applied to their 1981 box set, “Tangerine Dream ‘70-’80,” that included starting the chronological set with an excerpt from their 1971 album, “Alpha Centauri” -- as if to keep it tidily in the synthesizer zone by excluding all the earlier abominations that were contrary to latter-day, genre-specific affirmations.

Not only was the title of that rather expensive box set confusing (though not nearly as unwieldy as carting that hefty, 4LP-plus-booklet brick home on foot), but it was also a little disingenuous upon discovery that there were two records not represented from the discography. One was their first album from 1970 and the other was a single with the mysterious title, “Ultima Thule.” What gives: before 1981, I never even knew (nor would have suspected) that Tangerine Dream had recorded a single -- let alone with both of its sides unavailable anywhere else. But if this was the definitive, multi-LP box set with a deluxe colour booklet it looked every inch to be, then why were these records left out in the cold?

Eighteen years later, I scored an expensive repress of “Ultima Thule” in a PVC silk-screen sleeve and discovered why. It was beyond revelatory: it was both stunning and heavy. It was also everything I love about music all in place on one 45. But how could Tangerine Dream have recorded something so off their otherwise near-exclusive electronic programme AND spearheaded with such a prominent guitar attack? (Well, that’s exactly what graced their debut album, “Electronic Meditation” for half the time when for years I’d see it listed and only be able to imagine that it was probably too abstract or quiet for inclusion in that box set. As if!) Then again, not until the “Phaedra”/“Rubycon” pair did any two Tangerine Dream records even sound remotely alike in approach. Either the result of fluctuating lineup changes or a conscious effort made by Froese to constantly expand or aerate their sound (or both), one thing is certain: early on, Tangerine Dream were an extremely experimental group, unique as hell, and a group whose recordings stand up to decades of constant listening.

The first Tangerine Dream release to feature the trio of Edgar Froese, Chris Franke and Peter Baumann arrived in the unlikely form of that aforementioned 45rpm single, “Ultima Thule.” Unlikely not only because it wasn’t a full-length album (the entire two-part instrumental running for seven and a half minutes) but its A-side, “Teil 1,” displayed Tangerine Dream as an agitated, guitar-led power trio whose unreasonable heaviness was matched only by the strident use of mellotron and ambidextrous drumming that simultaneously propelled the piece into the equally unlikely region of garage punk as played with progressive instruments. (But in 1971, there was a significant amount of West German Frei-Rock of the most proto-metal kind being flung around: From Ash Ra Tempel’s pulverising “Amboss” to Kraftwerk without Ralf/with Rother on Bremen Radio with their Sabbath-like “Heavy Metal Kids”; to Amon Düül II’s rendition of “Eye Shaking King” on Beat Club; to Guru Guru’s “Spaceship” and back again to Silberbart’s entire “4 Times Sound Razing” album, the evidence is irrefutable, and heavy as lead boots.)

“Teil 1” is the theme from “Fly And Collision Of Comas Sola” from “Alpha Centauri” with its tempo wildly accelerated as Froese directs the group to assist him in getting out the last of his ya-yas left over from his previous errant guitar episodes on “Electronic Meditation” -- Which he does via his ostensible Fender Esquire with a manic guitar scrawl of Barrettonian proportions. It’s up there with Syd’s brilliantly anarchic solo on “Take Up Thy Stethescope And Walk” -- only rendered as a single airburst and not a strafing run. Once the smoke clears, Froese shifts into a prendulum rhythm of slashing, slow downstrokes at full stentorian power until a stunned Franke and Baumann come to their senses, fall in and follow suit. Bucking like a galleon on raging seas, Froese’s slashing guitar burns through Baumann’s creakiest organ passages and Franke’s constant drum filling while ominous mellotron tones hang like overcast curtains throughout. It remains cyclical as it accumulates a constantly building momentum with the mellotron and organ shifting in prominence until sometime later and with cymbal rattling galore, it all culminates with a final majestic ribbon of mellotron closing it all into hissing silence.

Side two, “Ultima Thule, Teil 2,” opens in far quieter realms as it unfurls with prominent mellotron. As it evolves, constant tom toms and quick stabs of organ add further variations and additions on the main mellotron theme. Baumann’s organ soon sustains vertiginous echo, making it ripple out widely in waves. The only disappointing part is its premature fade, the sole reminder that it’s in reality the B-side of a single. But Tangerine Dream is such an elevating force that it, at least for several minutes in the thick of it, feels like it could go on forever.

Dedicated to the memory of Christophe F.