A CONVERSATION we wish we'd been privy to, featuring Rob Halford, the banshee vocalist of heavy metal gods Judas Priest, and Elizabeth II, the queen of England:

"She asked, 'Why is heavy metal so loud?'

"I said, 'You have to have it loud to bang your head, Your Majesty.' "

"She sniffed at that," Halford continues, though the queen would hardly have been the first to sniff at Judas Priest or heavy metal.

So, Rob, did you wear one of those fabulous leather-and-studs outfits you started sporting in the mid-'70s, giving metal the indelible image to complement its ineradicable sound?

Halford laughs.

"No, but I was dressed in black. I still had a part of me that wasn't diminished."

All this took place March 1 at Buckingham Palace at a royal reception recognizing British music and its contribution to the nation's culture and economy. Among those attending: singers Charlotte Church, Cilla Black and Shirley Bassey; Roger Daltrey; Phil Collins; former Spice Girl Geri Halliwell; and a murderers' row of ax men that included Brian May, Eric Clapton, Jeff Beck and Jimmy Page (whom the queen asked, "Are you a guitarist, too?").

And Halford, reunited with Judas Priest after a 12-year break.

"That was very surreal, going to Buckingham Palace," Halford said recently, calling from Chicago before a Priest show. "It was the first time the royal family -- The Firm, as it's called -- wanted to give a nod to the music industry in general. My mother was more excited about it than anyone else, but it was magical for me, too, because I'm a royalist. I love the royal family, for all its imperfections, but to actually meet the queen! That was a thrill and a memory I'll always cherish."

Still, Halford says, "it was a bizarre day. I flew out of Oulu, Finland, that morning -- it was about 37 degrees below zero -- and two hours later I was in Buckingham Palace talking to the queen. And the next morning, I flew back to Tampere in Finland and the next show."

Finland was one stop on a sold-out European tour that confirmed Judas Priest is back and still a commercial force. The tour that brings the band to Nissan Pavilion on Sunday is its first headlining in American arenas since the early '90s, incidentally the last time Halford fronted Judas Priest, whose other members are guitarists Glenn Tipton and K.K. Downing, bassist Ian Hill and drummer Scott Travis.

That lineup made its re-debut last summer, sharing co-headline status on the Ozzfest tour with Black Sabbath, the other band from Birmingham, England, that can be held responsible for heavy metal. Getting back together was a headbanger's dream and obviously a wise move for all. Judas Priest's Halford-less albums and Halford's ventures with the bands Fight, Two and Halford were not exactly commercial triumphs, and "Angel of Retribution," the first new Judas Priest album in four years and the first with Halford in 14 years, opened at No. 13 on its March release, the band's highest chart position ever. Critically acclaimed, it sold more copies in its first week than its predecessor, 2001's "Demolition," did in four years and went Top 10 in a dozen countries around the world.

Halford, who once declared that "metal is dead" (and quickly apologized) feels late-blooming vindication.

"I think it's true to say there's been some respect afforded of late. And I think it's true to say that [heavy metal] has always been viewed as an underdog under the great umbrella of rock 'n' roll. Now certain aspects of it are being accommodated and given approval to, and Judas Priest is one band that's receiving that type of recognition."

Deservedly, of course. Black Sabbath's minimalist, doom-laden crunch may be the progenitor of heavy metal, but by speeding it up and injecting drama and dynamics, Judas Priest made it the sound of blue-collar adolescents worldwide. Of course this was after Judas Priest (the name taken from a Bob Dylan lyric) started in 1969 with a different lineup and a shifting identity -- pop-rock cover band to prog rock to blues rock before finally striking metal with what was then an innovative two-guitar attack.

Halford, a one-time theatrical lighting tech possessed of ear-splitting leather lungs, signed on in 1973, though success wouldn't be hinted at until 1976's "Sad Wings of Destiny" album. The late '70s and early '80s brought such hit albums as "Stained Class," "Hell Bent for Leather," "British Steel" (with metal standards "Breaking the Law" and "Living After Midnight") and "Screaming for Vengeance," featuring "You've Got Another Thing Coming," the band's only charting single in the United States (at No. 67). The leather-and-studs look had arrived with "Hell Bent for Leather," its roots in the gay subculture apparently lost on Priest fans. Halford finally came out in 1998, but fans hadn't cared one way or the other about one of rock's worst-kept secrets, just as long as he could scream onstage astride a Harley-Davidson.

Momentum stalled in the mid-'80s when the parents of two teenage Judas Priest fans from Reno, Nev., who had attempted suicide, one of them successfully, brought a $6.2 million suit against the band, alleging that a subliminal message had been encrypted in the song "Better by You, Better Than Me" (ironically, a Spooky Tooth cover). If played backward, the parents claimed, a voice could be heard saying, "Do it." The two boys shot themselves after repeated listenings to the "Stained Class" album while smoking marijuana and drinking alcohol. In summer 1990, band members spent six weeks in a Reno courtroom before the judge rejected the suit.

Later that year, Judas Priest returned to form on the "Painkiller" album, but there were rifts among the riffs. Halford wanted to explore new directions on a solo album, but the only way he could do so contractually was to quit the group. Which he did in 1992, famously replaced by Tim "Ripper" Owens, who'd been fronting a Judas Priest tribute band in Cleveland (later inspiration for the film "Rock Star").

"On the back of what we'd gone through in the Reno trial, and the extremely lengthy 'Painkiller' tour, which was a success but had a lot of physical and psychological things going on around it, what I should have done at the end of that tour is say, 'Guys, I'm going, you won't see me for a year,' " Halford says.

The break between Halford and Judas Priest would last more than a decade, with reconciliation coming in odd ways -- in 2002, Halford invited his old friends to his parents' 50th wedding anniversary -- and obvious ones, such as needing to work together on 2003's "Metalogy" box set celebrating the band's 30th anniversary.

"At the time all of us were so connected with whatever work we were doing we didn't really have that much of a period of reflection to ponder the what-ifs and the whys and wherefores and shoulda-coulda-wouldas," Halford says. "But in the recent months, it's gone through my mind: What could we have done, what could we have achieved, in that decade that we were not in each other's company?"

"Of course, Priest was still going," he points out. "Priest was still maintaining its point of view in metal. But the recognition of the band on this release -- on a global level -- says a lot about the need and the demand for the original lineup to get back in place and that the chemistry that happens in the writing between Glen and Ken and myself is a vital spark to this band's popularity. It's no different than the Stones or Aerosmith or AC/DC or Kiss -- any of the career rock 'n' roll bands that need to be in the shape that they need to be in."

And, yes, Halford followed Ripper Owens's exploits with his band.

"Oh, absolutely, because I'm as much a fan of Judas Priest as I am in it. I love this band's music and its performances, its personalities, quirks and idiosyncrasies. I love everything about Judas Priest."

And about Black Sabbath, it turns out. On Aug. 26, Halford found himself fronting his fellow Birminghamites at an Ozzfest stop in Camden, N.J. As Halford tells it, "Sharon [Osbourne] called me at my hotel -- I thought she was calling about the real nice birthday gift she and Ozzy sent the day before [beautiful handmade luggage adorned with skulls and crossbones]. She said, 'I'm not really calling about that,' and something went off in the back of my mind, 'It's something about Ozzy; he's not well.' "

Ozzy, in fact, had bronchitis.

"Sharon asked if I would step in, and my first question was when do you want me to do it? 'Tonight. C'mon, love, you're a big Black Sabbath fan, you know all the songs.' "

Halford boned up watching a concert video on the tour bus, got off to do the Priest show, showered and then headed back to the stage. "It was a thrill, and I just went out and did my best," Halford says. He has a bootleg video of the Camden show, "but I can't watch it. It's Judas Priest at the top of my fan list and then Black Sabbath, and it freaks me out to look at myself on stage with Tony [Iommi], Geezer [Butler] and Bill [Ward]."

A video he has watched is "Heavy Metal Parking Lot," the infamous 16-minute documentary by local filmmakers Jeff Krulik and John Heyn. It captured the social interaction outside a 1986 Judas Priest concert at the old Capital Center, where mullet-sporting fans waxed poetic about Priest and metal. VH1 (which is sponsoring the band's current tour) ranked the film No.16 on its list of "100 Most Metal Moments"; Revolver magazine ranked it No. 3 in "The 50 All-Time Hardest Rockin' Movies," and Spin ranked it No. 6 of the "20 Best Music Movies Ever." Director Cameron Crowe ("Almost Famous") has called it one of the greatest rock movies ever.

"It's a microcosm of what goes on, not just a Priest show, but at a heavy metal show even today," Halford says. "It's good satirical sociology there. It's been examined to death by everybody, and it will always be there, won't it?"

Halford doesn't know the half of it: An upcoming DVD has three hours of content, including directors' commentary, parking lot alumni reunions, outtakes and such sequels as "Neil Diamond Parking Lot" and "Harry Potter Parking Lot." And Krulik and Heyn are looking to develop their short into a feature film.

Halford's response: "That'd be cool to see."

JUDAS PRIEST -- Appearing with Queensryche Sunday at Nissan Pavilion.

Back in black: Judas Priest's Ian Hill, left, K.K. Downing, Rob Halford, Glenn Tipton, Scott Travis are reunited.