As front man for mid-60s British invaders Them, Van Morrison was a powerhouse vocalist of the first rank, miles beyond plodders like the Yardbirds’ Keith Relf and callow R & B mimics like the young Mick Jagger. In fact, only Stevie Winwood and Eric Burdon could match Morrison for intensity, and neither of them could compare on the songwriting front. Whether recharging old favorites (“Baby Please Don’t Go”) or crafting supercharged new ones (“Gloria”), the young Irishman brawled his way to the forefront of the myriad bands nicking American sounds for transatlantic gains. When Them dissolved after two albums, Morrison seemed likely to become another tough-hearted, blue-eyed solo soulster; his first album without the band, Blowin’ Your Mind, bore out this promise while showcasing such ebullient pop compositions as “Brown Eyed Girl.”

Many singers would have been content to rest on those laurels. Some, like Burdon, did. But Morrison soon proved he was a star of a wholly different order. Decisively ending his R & B apprenticeship with a pair of astonishingly mature recordings–the hypnotic pop-jazz of Astral Weeks and the perky bed-sheet soul of Moondance–he went on to become one of the most influential figures of the pop era, as important in his own way as Dylan or Miles Davis. Staking out two types of ground–eight-minute spiritual odysseys and three-minute hit singles–Morrison never betrayed the jazz and R & B tradition that undergirded his earliest successes. Throughout the 70s he worked this territory to brilliant effect; albums like St. Dominic’s Preview and Into the Music consolidated the gains of his early solo work, and even his lesser efforts (the gnomic Hard Nose the Highway or the diffuse A Period of Transition) were worthy projects, failures only by his high standards. After a brief slump in the early 80s–dalliances with lit-rock and fusion resulted in music of stupefying dullness–Morrison renewed his lease with his muse. And while his annual albums now contain a certain percentage of filler, he’s still capable of focusing his talent for marvelous soul excursions (“Orangefield,” “Professional Jealousy”) and even the occasional pop hit (“Real Real Gone,” the 1991 soul burst that proved he wasn’t).

Now, rolling into his fourth decade as a recording artist and more than assured of a place in the rock pantheon, he’s delivered the sprawling A Night in San Francisco. Recorded live last December, the album is a scheduled stop of sorts: every ten years or so–first with the 1974 It’s Too Late to Stop Now and then with the 1985 Live at the Grand Opera House, Belfast–Morrison has checked in with a concert release. And while those two albums are among the bright spots of his recording career, anyone who’s caught Morrison onstage (he last passed through Chicago last spring, for a pair of shows at the Civic Opera House) can attest that seeing him live is a dicey business. A temperamental performer, Morrison needs a certain mood to deliver a striking show; when he doesn’t connect with the audience, he’s liable to get stuck in a mid-tempo rut or to disengage with a sharp inward turn, wandering through his back catalog with total disregard for paying customers.

From its first moments–a soaring rendition of “Did Ye Get Healed?”–the San Francisco show allays any fears of slackness. Morrison is alert and energetic, whether punching out the driving R & B of “I’ve Been Working” or bringing down the volume (and the house) for “Tupelo Honey.” Much of the responsibility for a live show of course belongs to the supporting cast, and Morrison is aided and abetted by longtime associate Georgie Fame on organ, as well as Ronnie Johnson on guitar, Kate St. John on oboe and saxophone, and Haji Ahkba on fluegelhorn. The show’s harder-edged moments–like a sharp rendition of “Make It Real One More Time”–are boosted by the confident alto sax of European funk-jazz siren Candy Dulfer, known primarily for her work with Prince. Even in less auspicious moments, such as a fair-to-middling performance of “Beautiful Vision” by Morrison’s daughter Shana, the band stays tight, and Morrison always returns, booming, implacable, to lead the caravan onward and upward. When all cylinders are firing, when the band is joyfully unwrapping “You Make Me Feel So Free” or “It Fills You Up,” Morrison ignites both the vocal lines and the spaces between them, achieving a pure spirituality that few performers ever have–Marvin Gaye, perhaps, or Peter Tosh.

Original material is only part of the story. One of Morrison’s earliest hits, “Baby Please Don’t Go,” was a cover of a Big Joe Williams chestnut, and Morrison has been repaying his debt to American soul with interest ever since. It’s Too Late to Stop Now contained overt homages to Otis Redding, Sam Cooke, and Ray Charles, among others; as this set shows, these are still his touchstones. Recently, as he’s cemented his passage from acolyte to legend, Morrison has put these influences on full display, often bringing his blues and R & B favorites onstage with him. In fact, these days it’s difficult to imagine a Van Morrison concert without a slew of special appearances by blues forerunners, and the San Francisco concert rolls out raspy belter Jimmy Witherspoon for “Have You Ever Loved a Woman?” and harp legend Junior Wells for “Good Morning Little Schoolgirl.” While this kind of tribute can verge on tired shtick–watch amazed as musical generations interpenetrate!–both Witherspoon and Wells acquit themselves admirably.

Seamlessly weaving his influences into a tapestry of Caledonian soul, Morrison also practices his own brand of sampling, breaking out of the current song to include a snatch of another composition. This technique, which allows him to range freely over the music universe, from blues to soul to folk to funk to jazz to big band, might seem precious or pretentious in the hands of other artists. But Morrison’s inimitable style smooths the seams; copping lyrics from Dylan’s “All Along the Watchtower,” he never gives an inch, and when he absorbs Sly Stone’s “Thank You Fallettinme Be Mice Elf Agin,” there’s hardly any irony. Some of the interpolations may seem willfully eclectic at first (“Moondance” interlaced with “My Funny Valentine”?), but Morrison pushes the compositions together until their kinship is undeniable. He finds the common ground finally by being the common ground.

For the encore, of course, the band locks into “Gloria,” and John Lee Hooker even punches in for a grumble or two. But the peak of the show comes almost an hour earlier, when Morrison repaves Doc Pomus’s “Lonely Avenue” with nearly a dozen other classics, from “Be-Bop-a-Lula” to “Family Affair.” And Morrison’s grand tour through James Brown’s epochal “It’s a Man’s Man’s Man’s World”–the backup vocalists walk frozen ropes, the band keeps the action taut for what seems like hours–proves once and for all that it’s Van’s Van’s Van’s world.