Nobody quite understands Van Morrison. If Bob Dylan’s long stretches of patent bizarreness in the 1980s seem incomprehensible to most, then Van Morrison’s entire career surely must remain an enigma. His music has encompassed nearly all of rock and roll in the past fifty years, from the frantic youthful energy of “Gloria” in 1964, to the Christian hymn “Full Force Gale” in 1979, to the contemplative introspection of “Celtic New Year” in 2005. Meanwhile, his 1974 album “Veedon Fleece,” celebrating its 40th anniversary this month, is a quietly overlooked masterpiece. It is integral to our attempt at understanding the Irishman, and without it our portrait of Van Morrison would be woefully lacking.

On “Veedon Fleece,” what seems particularly evident is that Van Morrison, born in Belfast after the Second World War, draws from two vastly different sources of inspiration, feeding on the muses of Blake and Yeats as much as Fats Domino and Muddy Waters. The songs on the album compose a delightful array of melodies and instrumentation deriving from the mystical foggy landscape of Connemara in western Ireland, and from the bluesy grooves of the Mississippi Delta: We hear an inflected Gaelic fiddle, alongside a hopping piano. Indeed, this symbiosis appears all over Van Morrison’s oeuvre, especially on the soul-inflected “Moondance” and the religiously minded “Into the Music.”

The centerpiece of “Veedon Fleece” is “You Don’t Pull No Punches, but You Don’t Push the River,” a nine-minute song composed of so many lyrical ditties and wordless riffs that it feels like Van Morrison is making the whole thing up as the music carries him along. The song is replete with asides and references, largely to the Veedon Fleece, which might harken to the Greek myth of Jason and the Argonauts, but nobody’s really sure; we do know that William Blake and the Eternals are apparently searching for it all over the west coast of Ireland. A concern with authenticity comes to the fore as the song progresses — “We’re going down to the west coast/Lookin’ for the real soul, for the real soul people,” Van Morrison sings in a gruff drawl. At other points, his voice soars ever higher, trying to pierce its way into our souls. He can twist and modulate his voice like no one else, something wholly evident on the track.

“Bulbs,” coming later on the album, shows Van Morrison for the bluesman he really is, and though structurally and musically it differs from “You Don’t Pull No Punches,” it exhibits the same qualities of vocal improvisation and experimentation that make the former song so memorable. After an acoustic introduction, “Bulbs” quickly becomes a lively bluesy piano-and-guitar shuffle, and the singer’s sharp voice seems to encompass every tone all at once. Near the middle of the track, he stops singing and begins a wordless growl, quickly undulating in volume. This vocal shift renders all instrumentation, as catchy as it is, secondary, and as on “You Don’t Pull No Punches,” forces us to consider the voice above all else.

Like much of Van Morrison’s work, “Veedon Fleece” is largely concerned with nostalgia. Van Morrison wrote the album after visiting Ireland in 1973 following a seven-year self-imposed exile in the United States. That might explain the free-flowing, loose Celtic sounds on the record, sounds that Van Morrison draws from the character of the land itself. No wonder, then, that so many of the songs concern themselves directly with the land — “Streets of Arklow,” about an ambulatory stroll through an Irish seaside town, sounds like a mournful reliving of the carefree joy of youth, and “Cul de Sac” impresses on us the enormous sadness of returning to a changed boyhood home. This record is firmly, insistently about Ireland, a topic always present in Van Morrison’s work but never quite properly addressed until this point.

But in 1974, Ireland found itself in the throes of civil war, with Republicans, Unionists and the British Army all fighting for the fate of Ulster in the North. It is remarkable that Van Morrison never once mentions this consuming struggle of which his hometown, Belfast, was the heart. Indeed, in his entire career, I know of only one reference to the Troubles, and that an oblique remark about orange boxes, typically associated with the Unionist Orange Order, in the song “Saint Dominic’s Preview” in 1972. Perhaps we might glean from this that Van Morrison believes in a nostalgic, romanticized conception of Ireland — a Celtic Ireland, the Ireland of Yeats and St. Brendan and Padraig Pearse. The past dominates all other substantive themes in Van Morrison’s work, and humans cannot escape the burden of the years that have come before. But we can hope for a shining future rejuvenation, and that hope permeates “Veedon Fleece.”

Like most music, the album is fundamentally about the search for some sort of meaning. But Van Morrison thinks differently about the origin of that meaning. For him, it is neither the words nor the melodies that render a song impactful, but rather the sounds that come from the singer’s mouth. Van Morrison’s career, in fact, seems like one long attempt to make words meaningless and sounds supreme, which he accomplishes by repeating the same phrase over and over again. On “You Don’t Pull No Punches,” he repeats the title phrase endlessly near the end of the song, using everything from fuzzy snarl to clear falsetto. On Astral Weeks’ “Madame George,” Van Morrison’s best song, the coda features the line: “The one’s to love the love the love’s to love the love’s to love to love to love…” On “Tupelo Honey,” the sweetest love song ever written on the album of the same name, the singer delivers the line “She’s alright to me” in every way possible. The effect in all three songs is to render the words meaningless; all that matters is his interpretation of them. We transcend the mediated meaning of words and enter the higher understanding brought through sound itself. This is not a new concept for Van Morrison, but only on “Veedon Fleece” does it reach its fullest and most lasting realization.

“Astral Weeks,” the paragon of sadness in music, was Van Morrison’s greatest achievement. It resembles no other album extant today, and only four records can claim to better it. But “Veedon Fleece” was a more important album for Van Morrison—the entirety of his work for the last forty years derives from its rejection of aspirations to grandeur and from its quiet, contemplative focus. Music critics have largely seen Van Morrison’s work since Veedon Fleece as mediocre, the creation of a worn-out, grumpy man. Greil Marcus described the sixteen records from 1980 to 1996 as “an endless stream of dull and tired albums.” Robert Christgau gave them all B- and C+ grades. But these diagnoses are too pessimistic and their analyses too unfair to the artist. “Astral Weeks” was a lyrical and musical masterwork, and while Van Morrison’s albums since “Veedon Fleece” are strong in lyrics and in instrumentation, their brilliance lies in his singular focus on vocal sound. Listen to the harsh roughness on the self-analytical, self-critical “The Healing Game,” or the high clarity on the spiritual “Into the Music,” or the sweet tenderness on “Poetic Champions Compose.” The lyrics are often repetitive and simple; the music of little interest. Van Morrison’s voice captivates us, reigns over all. That is the surviving legacy of “Veedon Fleece”: its improvisational spontaneity provides us with the insight that words, ultimately, mean rather little. And only with that understanding can we begin to interpret Van Morrison’s career.