The last three years in the life of Metallica have been a soap opera that makes The Osbournes look like General Hospital. The low point may have been a long 2000 interview that appeared in the April 2001 Playboy in which the writer, Rob Tannenbaum, talked to the four members individually, since it appears they weren’t speaking to one another. Guitarist Kirk Hammet as much as admitted that Tannenbaum was being used as an intermediary for airing long-standing grievances. Bassist Jason Newsted, anguishing over the abuse he felt he’d suffered at the hands of his bandmates for more than a decade, and beside himself at singer/guitarist James Hetfield’s injunction against the release of Newsted’s Echobrain side project, stopped just short of calling Hetfield a despot and a hypocrite. Lars Ulrich topped that by calling Hetfield "homophobic"; Hetfield returned the favor by describing Ulrich as a lousy drummer and a spoiled rich kid whose big mouth — specifically on the issue of the band’s publicly disastrous but privately effective war against Napster — was always getting the band into trouble. "I don’t mind being looked at as the asshole within the band," Hetfield cracked, "as long as the fans think Lars is the asshole."

Long before the interview hit the stands, Newsted quit — and the band hit crisis mode. In January 2001, manager Cliff Burnstein brought in a professional-sports-team motivator to babysit the remaining three members while they learned, after 20 years of conquering the world together, how not to hurt one another’s feelings. (This premise is at least as funny and sad as The Osbournes’ portrait of a heavy metal family; and since Paradise Lost filmmakers Bruce Sinofsky and Joe Burlinger have been following Metallica around for the duration of the drama, we may yet get a first-hand look at it.) By March 2001, Hetfield and Ulrich were preaching a touchy-feely conversion and hinting that their long run as Metallica’s exclusive songwriting team was over. "What we want to get is a complete honest way of writing," Hetfield told the fanzine So What. "And before, it was — well, looking back, it worked completely. But, you know, if I was Kirk . . . " The implication was hard to miss: Metallica’s successful creative dictatorship would have to give some ground in the name of band unity.

Suddenly, though, that all seemed moot: in July 2001 — three months after the band had returned to the studio for the sessions that would become the new St. Anger — Hetfield packed himself off to rehab. For the first time since the death of bassist Cliff Burton, in 1986, the future of Metallica seemed to be in serious jeopardy.

METALLICA.COM MESSAGE BOARDS have become a fan-on-fan war zone since the release of St. Anger early last month. The album, which debuted at the top of the Billboard 200 album chart despite a short sales week (it was rushed out several days ahead of schedule, after its songs were leaked on line), has nonetheless become the most divisive item in their catalogue since the "Black Album" (1991’s Metallica — all the band’s studio albums are available on Elektra). Detractors have displayed pious indignation over Metallica’s refusal to return to the thrash of their ’80s glory years, and over their delivering instead a disc that sounds like rehearsal tapes from a local suburban new-metal outfit — a ponderous, sketchily recorded collection of eight-minute songs with scratchy vocals (not always in key), a tinny, obnoxious drum racket shoved high into the mix (and also out of tune), and no guitar solos. One critic, who got an advance listen to St. Anger in the Elektra offices, panicked after turning in his review because he thought the label might’ve accidentally played him demos instead of the finished album.

Adding fuel to the haters’ fire was an interview given by producer Bob Rock — who has helmed the band’s studio efforts since Metallica — to MTV.com that was published under the heading "What’s Up with the Sound on the New Metallica Record?" (Rock, who receives co-writing credits on St. Anger, played bass in Newsted’s absence on the disc; former Suicidal Tendencies bassist Robert Trujillo has since been hired away from Ozzy Osbourne’s band to fill the bass slot, a move that prompted Ozzy to retaliate by hiring Newsted. Meanwhile, Metallica have responded to OzzFest by mounting their own metallapalooza, the Summer Sanatarium Tour that comes to Foxboro this Sunday.) Rock described the process behind the album as a series of open-ended jam sessions, all of which were recorded with cheap microphones and then fed into a computer, where the songs were assembled by cutting and pasting pieces together. Vocals were rushed through in one or two imperfect takes and, in a radical departure from contemporary hitmaking orthodoxy, were not digitally "fixed." As an example of why all this was a good thing, he cited William Burroughs and Karel Appel — though his description of the process suggests, in a much more mundane context, almost exactly the way the Rolling Stones have cobbled together their latter-day albums. "Technically, you’ll hear cymbals go away and you’ll hear bad edits," Rock told MTV. "I’ve spent 25 years learning how to do it the so-called right way. I didn’t want to do that anymore."

There is more than a little irony in seeing Rock, the man who fine-tuned Metallica to within an inch of utter sterility throughout the ’90s, suddenly transforming himself into a Steve Albini type. And there is justifiable skepticism at seeing the multi-million-dollar monsters of rock turn in a disc that makes Metallica’s own Garage Days Re-Revisited (Elektra, 1987) sound like a Justin Timberlake product. As one respondent on metallica.com pointed out, St. Anger might be the most overproduced underproduced album of all time.

Despite all the rending of hair and gnashing of teeth, St. Anger has received an overwhelmingly positive critical reception. And that has bolstered the case of the album’s defenders, who argue that St. Anger is the band’s best album since Metallica, that a return to the formula of Master of Puppets and Ride the Lightning would’ve been a creative cop-out, that heavy-metal studio albums have long been the product of extensive post-production editing, and that St. Anger’s lo-fi sound gives rawness — and by extension realness — to a band who have been known, every now and again, to overproduce the living daylights out of their music.

I SUSPECT THE FINAL VERDICT on St. Anger will eventually be something along the lines of "coulda been worse." Like the Stones in the late ’70s and Black Sabbath in the early ’80s, Metallica are searching for a new way to be themselves — and as such they’re subject to a mess of contradictory impulses. Metallica’s master trilogy — Ride the Lightning (1984), Master of Puppets (1986), and . . . And Justice for All (1988) — emphasized a rugged, boxy architecture, a sound in tune with the automated clank and crunch of mechanized infantry.

In Ian Christie’s recent Sound of the Beast: The Complete Headbanging History of Heavy Metal (Harper Entertainment), the late Cliff Burton is quoted saying about Master of Puppets’ "The Thing That Should Not Be": "It’s about huge things marching around! Huge fuckers so big they compete with buildings in size!" In the ’90s, Tool and Korn turned metal inside out, summoning the slither of a contaminated, corporeal ooze. On St. Anger, Metallica do their best to combine the new and the old — for starters, they’ve tuned down to C (E being the lowest note on the lowest string in traditional guitar tunings), and that puts enough slack in their strings to put them in Korn’s low-rider league. The results are mixed. It’s true that after the tepid Load (1996) and Reload (1997), St. Anger’s satisfying bursts of aggression are a relief. The title track and "Some Kind of Monster" give Ulrich an excuse to rumble with both feet, and they permit Hammet and Hetfield to unleash their patented jackhammer rhythm-guitar roar on a new generation.

But one of the revelations of the band’s MTV Icon special was how incompatible Metallica’s songs were with the new-metal bands assigned to cover them. Korn and Limp Bizkit couldn’t help bleeding around the sharp edges of Metallica’s fortress-like anthems. By contrast, Sum-41 and Avril Lavigne adapted just fine, Metallica’s chiseled rhythm-guitar workouts having been a much bigger influence in the ’90s on Offspring-style pop punk than on mainstream metal, where post-Metallica death metal, grunge, and hip-hop were the main ingredients. It’s tempting — so tempting it’s already become a cliché of St. Anger reviews — to see the album as a long-delayed follow-up to their 1983 debut, Kill ’Em All (Elektra), which was itself a consolidation of prevailing metal styles. (Hetfield suggests as much by reprising a lyrical snippet from Kill ’Em All’s "Whiplash" on "St. Anger.") But the hard truth remains that in Metallica’s bid to remain relevant, the former leaders of the metal pack have become followers.

What’s more, Metallica are by their own admission a wounded animal, and they’re making wounded-animal noises. St. Anger isn’t pretty, and it’s barely art; it’s mostly just pain, unmitigated by the sophisticated lyrics and meticulous, symphonic compositions that have defined the band’s best work. This unmediated approach accounts for the album’s best and worst elements, which sometimes appear within a single song. I’m partial to the grindcore intensity of the leadoff track, "Frantic," which boils over in panic, rage, and confusion, with Hetfield looking over his shoulder at the wreckage of life. But they lose me in the bridge, where Hetfield’s rap-core barking of "My life style! Determines my death style!" makes him sound like a new-age-sobriety drill sergeant.

For his part, Hetfield has seen The Thing That Should Not Be, and it is him. On St. Anger, he finishes the sentences that Newsted wouldn’t complete in the Playboy interview: the gist of it is, he’s a despot and a hypocrite — albeit one intent on contrition. "Dirty Window" deals most explicitly with Metallica’s power struggles ("I drink from the cup of denial/I’m judging the world from my throne"). "Shoot Me Again" tempers Hetfield’s impulse to martyrdom with doubts about the cost ("All the shots I take/What difference did I make?"). And "All Within My Hands" distills his authoritarian streak to a bluntly desperate chorus ("Love is control/I’ll die if I let go"). Mostly, though, this is an album of quotidian questions: "Why me?" ("Untamed Feeling"); "Am I who I think I am?" ("Dirty Window"); "Won’t you help me?" ("Purify"); "Can’t you help me be uncrazy?" ("Untamed Feeling" again, in a line uncannily echoing TLC’s "Unpretty").

To hear Hetfield tell it, a life in heavy metal is one you wouldn’t wish on your worst enemy. In 1983, he was an angry young man who hated the world; 20 years later, he’s an angry middle-aged man who hates himself, "madly in anger with you," the anger now an icon tattoo’d ’round his neck. All told, the new Metallica album is a bit of a miracle, if only for the fact that they were still around to make it.

Metallica’s Summer Sanitarium tour, featuring Metallica, Limp Bizkit, Linkin Park, Deftones, and Mudvayne, comes to Gillette Stadium this Sunday, July 6; call (617) 931-200.