Running through August, the highly anticipated Metal Masters Tour kicked off Wednesday night at Camden's Susquehanna Bank Center with a dazzling doubleheader of winning theatrical metal from two roughly 40-year-old rock bands with roots in Birmingham, England.

Judas Priest headlined, opening with selections from their new double-CD "metal opera" Nostradamus about the 16th century French poet-prophet; they closed 85 minutes later after leather-loving frontman Rob Halford rolled out on a motorcycle for a three-song encore climaxed by "You've Got Another Thing Coming."

Heaven and Hell earlier delivered over 70 polished minutes ending with a 15-minute version of their namesake song, also the title track of their 1980 album (the first Black Sabbath record on which American Ronnie James Dio replaced the fired Ozzy Osbourne; adopting the current band name upon reuniting last year, Dio and guitarist Tony Iommi et al. are working on a new album due next year).

Lone American band on the bill Testament launched the tour promptly at 5:30 p.m. before a smallish throng. (Internationally influential, the darker mid-80s Bay Area contemporaries of Metallica are supporting this year's fine comeback disc The Formation of Damnation, Testament's first new album in almost a decade.)

Motorhead then thrilled a gathering crowd, loudly cranking through 45 minutes of career-spanning material that showed why they're celebrated as forerunners of speed-metal, punky thrash and hybrids thereof (if never claiming for themselves anything more than rock). "See, the new ones aren't so bad," cackled singer-bassist Lemmy Kilmister, an impossibly rugged 62 years old, still leading the band he founded in 1975 that bears his nickname acquired while in the English space-metal outfit Hawkwind. (Motorhead will release their 20th album, Motorizer, on August 26, and return to the Delaware Valley to finish their own headlining tour at the Electric Factory on September 19.)

Before exiting in a power-trio blaze of early songs including the inevitable, enduringly shred-tastic "Ace of Spades," Lem touched base and set things up. "Let's get into some rock 'n' roll -- remember that?" The band slammed into their mid-period "Going to Brazil," as exhilarating a Chuck Berry-based meta-rock ripper as there is, recounting in-flight shenanigans and an itchy anticipation to play, brimming with death-defying joie de vivre. It was another aural manifestation of the Motorhead M.O. and actual motto, seen on scattered shirts and tattoos around the SBC: "Born to Lose -- Live to Win."