Joe Cocker's career has been marked by more comebacks than a boomerang.

After sinking into obscurity following a wildly successful concert tour and album with Mad Dogs And Englishmen in 1970, Cocker, attempted to pick up the pieces, often presenting a pitiable spectacle as he continually fumbled in his quest for the old magic.

He drank heavily and popped copious amounts of pills but not nearly so much as press accounts said, Cocker, 34, now insists. His later tours were embarrassments, his performances disorganized and his state of health an occupational hazard to promoters.

His retching episodes between songs have been public record for some time. There were periodic surges of hope when he recorded the hit single, "You Are So Beautiful" and "I Can Stand a Little Rain" but the optimism was shortlived.

So, the Sheffield bantam would retreat once more, contemplate what seemed to be a wasted career and then try again.

He has acquired a new manager, his fourth. Michael Lang had produced the Woodstock Rock Festival and was favorably impressed by Cocker's United States debut at the mammoth outdoor extravaganza in 1969.

Cocker also recruited a new backup group from the Worcester area called the American Standard Band - Kevin Falvey, Deric Dyer, Cliff Goodwin, Howard Hersh and John Riley. He also enlisted three backup singers, the Oreos, comprising Clydie King, Mona Lisa Young and Ann Lang, the latter his manager's wife. Add old hand tenor saxophonist Bobby Keys, high-register trumpeter Phil Driscoll and another horn and you have considerably scaled-down version of Joe's former family circle.

Last Sunday night Cocker, carefully testing the waters by deliberately playing in smaller venues, performed a one-show stint at the Paradise. Sporting the same scraggly beard and a chest-high paunch, the new Joe Cocker delivered a zapping performance that left the capacity turnout cheering a comeback that had finally worked.

From his laconic walk-on at the beginning of "Cry Me a River," through "Feeling' Alright," "Delta Lady," "Guilty," "With a Little Help From My Friends" and "You Are So Beautiful" and, from his new Elektra album, "Luxury You Can Afford" - "I Can't Say No," "Whiter Shade of Pale," "Lady, Put The Light Out," "I Know," "Fun Time," the destined-to-be-a-hit single; "What You Did To Me Last Night," "Watch the River Flow," and "I Heard It Through The Grapevine" - Cocker was in command - and in full control.

He growled out the lyrics, as of old, in his No. 2 sandpaper baritone, and his arms dangled loosely, as if manipulated by strings. The setting was one of mass euphoria as Cocker sang an adrenalin-pumping set of finger-popping blues- rock.

When, at approximately midnight, he departed after a rousing "High Time We

Went," the good vibes rippled out onto Commonwealth avenue along with the customers.

The next afternoon Cocker, wiping the sleep from his eyes following a late-night reunion with Dr. John, sat at the edge of his bed in his Brookline motel room.

Yes, he said, he was pleased with the response to his just-completed "shakedown cruise" and was looking forward to a two-week vacation before resuming his tour in the southeastern part of the United States.

He recalled his first Boston visit, with the Mad Dogs And Englishmen tour, at Symphony Hall in the spring of 1970. The congestion onstage was likened to a scene at Filene's Basement as Cocker played patriarch to a huge company of performers, including an infant and a dog. It was a quasi-historic event in rock music and was hugely successful.

Strangely, this magical tour helped to ease the skids under Cocker's personal and professional life.

"My musical ideas had collapsed at the end of that tour," said Cocker in subdued tones, "and as soon as that happened my ambition seemed to leave me.

"The tour left me disillusioned with the rock-and-roll world in all its aspects, particularly management. So, that's why I sort of disappeared. For a start, I hadn't made any money out of the tour which upset me."

Still paying off debts and settlements accrued over the years, Joe Cocker today is a far more mature businessman.

"These days I feel secure the way my interests are split up. Now, there is more than one person involved in handling my finances," he said. "If anything gets out of hand, I can get the warning signal from at least one source."

Neither does his deportment get out of hand nowadays. While not completely dry, neither does he wallow in whisky nor is he the acid freak as a national news publication described him recently.

"I don't drink heavily anymore," said Cocker, who sips beer between songs. "After a gig I like to put a few doubles down. The writer (from the national magazine) got a bit carried away. He said I took 15 acid trips a day plus a bottle of scotch. Golly, I thought, he must have people thinking I'm a monster. I tried it only one time in my life. What I actually told him was that I once took 15 acid tabs and another time drank a full bottle of scotch before going onstage.

"You see, I had been living in Los Angeles for three or four years and I wasn't happy with my managerial situations so I tended to hit the bottle and get out of it that way which everyone knows about. I was trying to escape reality."

With Lang's guidance Cocker is putting the past behind him but first there's the matter of paying off an indebtedness to A&M, his old record label.

"A long time ago, I wanted a certain manager out of my life," said Cocker, "so A&M paid him off for me and I had owed that company $400,000 as a result. It feels more like $4 million.

"I figure I'll pay it off after my next couple of albums because I get a quarter of a million dollars up front on each album, so that will be straightened out."

Ahead for Cocker is a return head-to-head sing-off with John Belushi - he calls him "Beloosh" - on television's "Saturday Night Live." To put it mildly, Cocker does not consider Belushi's impersonation flattering.

"We'll see what comes out time," said Cocker. "I've only seen that takeoff by him once and have always been surrounded by people who absolutely deplored it.

"For one thing I approach my music differently these days. As you grow, you do change."

Conspicuous by its absence last week at the Paradise was the fabled herky- jerky guitar simulation that, according to the artist's assessment, eventually became a cross to bear.

"I did all that stuff for publicity years ago when young people would describe me with such words as "spastic' and "palsied'," he said. "It made me stop and check out what I was doing.

"Recently, while having some pictures made, I came across this photographer's young assistant, who must have swallowed all of that publicity. She really expected me to walk in wearing leg braces."