It was reasonable to speculate that with the Ozzfest tour on hiatus the past two years that Ozzy Osbourne had finally lost it -- mentally, vocally or otherwise ... as in, beyond mumbling to himself in the garden as he did on "The Osbournes."

Happily, we can go ahead and dispel that notion. The Prince of Darkness seemed to be mostly there Thursday night at the First Niagara Pavilion for one of only six Ozzfest dates in the U.S. this summer.

True to form it was a day that got progressively more melodic as it wore on, starting in the parking lot with the more fierce and growling sounds of Kingdom of Sorrow, Drowning Pool and others from the nu-metal age.

The overlord of the second stage was classic metal throwback Zakk Wylde, previously doing double duty on recent tours leading Black Label Society and serving as Ozzy's axeman. This time his fiery licks are reserved for BLS, and he just about turned the hot asphalt into lava Thursday during a "Godspeed Hellbound" solo that stretched beyond five minutes.

The guitarist was still raging when Nonpoint launched the main stage with a brief nonthreatening set that could have been buried on stage two. DevilDriver, on the other hand, stirred up something more brutal, recalling the mayhem and precision of Pantera topped by an underworld roar from ringleader Dez Fafara.

DevilDriver was just demonic enough on songs like "Fate Stepped In" to provoke a violent circle pit on the lawn. The more chilled-out folks in the pavilion were prodded with the challenge: "Do you remember when you were young and stood up at concerts?" (True enough, this Ozzfest was different from its heyday when a seething mass of black-clad metalheads filled every niche of Star Lake and set fire to the lawn.)

Rob Halford knows a little about driving the devil around, and the Judas Priest singer, in his studded leather coat, took it for a spin with his project Halford, delivering forceful old-school speed metal. He soared over top of it with ear-shattering operatic vocals that are as distinctive as the genre ever produced. In the biggest change-up of the day he employed an autotune vocal intro for the otherwise formulaic new song "Made of Metal." The crowd took it in with neither disdain nor excitement, whether it was Halford's "Crystal" or Judas Priest's "Never Satisfied."

Motley Crue came out with fireworks and "Kick Start My Heart," flipping the tone of the day to a sexier L.A. party vibe. The Crue's satanic offering was a fist-pumping "Shout at the Devil," with Vince Neil's vocals at a fever pitch. Don't know how the DevilDriver pit crew felt about it, but the rest of the Ozzfesters were up and screaming as the Crue sounded no worse for all that wear on pop-metal classics such as "Looks That Kill," "Live Wire," power ballad "Home Sweet Home" and show-stopper "Girls, Girls, Girls."

After a hilarious video montage of Ozzy set in everything from a "Jersey Shore" scene to a Lady Gaga video, the metal godfather hit the stage in his black cloak, jumping up and down for "Bark at the Moon" and the new offering "Let Me Hear You Scream."

Greek guitar hero Gus G, the most jaw-dropping musician of the day, proved his metal by navigating the sinewy and sinister leads of "Mr. Crowley" and Black Sabbath's "Fairies Wear Boots" and later leading a heavy blues jam with the band, which killed it on "Iron Man."

Ozzy -- shooting his watergun, doing jumping jacks and calling for screams -- wasn't hitting the high haunting vocal peaks he once did, but in his best moments he wasn't far off.

Even in his worst moments, like driving "The Road to Nowhere" into the ditch, he's still Ozzy, and with this crowd it's a blood bond.

Critics Andrew Druckenbrod and Scott Mervis talk about music on "The Beat," available exclusively at PG+, a members-only web site of the Pittsburgh Post-Gazette. Our introduction to PG+ gives you all the details.