SACRAMENTO — Aftershock, Northern California’s heaviest rock and roll festival, returned in all its metal glory to Discovery Park Thursday for its 10th year. With a lineup led by Slipknot, the first day the four-day event was definitely not a throwaway.

The grounds filled with thousands of mostly black-clad fans donning shirts of their favorites bands; the metalheads, punk rockers and emo kids coexisted in one diverse environment. In a way, it was fitting to have hard rock’s pseudo-ambassador Corey Taylor lead the first night’s bill, providing an ample welcome.

Slipknot

Slipknot’s set was as chaotic a spectacle as one might imagine, from the lights to the pyrotechnics and the stage design itself, with a pair of percussionists flanking each side with massive rigs. Vocalist Taylor spent much of the performance egging on fans and challenging them to bring more and more energy.

Opening with the unrelenting “Disasterpiece,” “Wait and Bleed” and “All Out Life,” Slipknot was unrelenting.

The material was a cross-section of the band’s catalog, with just one track representing new album The End, So Far. The thrills continued as Slipknot adeptly moved with a ferocious energy. Whoever was in charge of the band’s sound deserves credit for an admirable job mixing. Brutally heavy songs can sometimes sound muddy, but the band’s sound was crisp and tight.

Taylor often expressed appreciation for the fans that have kept the band running strong all these years.

“We got started as a band in 1999,” he said. “If you keep on supporting us, we’ll go 23 more years.”

Of course, the requisite hits were there, including “Before I Forget” and “Duality.” The crowd did its part to match Taylor scream for scream. As the band moved toward the end of its set, Taylor began teasing fans.

“Are you ready for one more song?” he asked after at least three songs to roars. After closing the main set with “Spit It Out,” the band eventually returned to deliver an encore.

“Are you ready for your national anthem?” Taylor asked before launching into “People = Shit.” The day ended on a lively note with Taylor asking fans to get down on their knees before having them explode back up with the music on “Surfacing.”

Rob Zombie

Godfather of shock rock’s set didn’t feel like a dramatic departure from his last appearance at the festival, but still delivered high-voltage thrills. Rob Zombie was energetic, attacking the stage from start to finish, while checking all the boxes with songs fans likely were hoping to hear. The hard rocker was in good spirits, sarcastically chiding the crowd.

“This song goes out to all the kids,” he said before launching into “Scum of the Earth.”

Of course, Rob Zombie mixed in tracks like “Living Dead Girl” and “More Human Than Human,” keeping up a quick pace. Before playing White Zombie cut “Thunder Kiss ’65,” Zombie offered up a challenge, asking attendees to put their phones away for three minutes to take in the song instead of “posting to TikTok or Instagram or whatever stupid place it ends up going.”

He rounded out the set with “Dragula.”

Evanescence

One of the highlights of Thursday came from hard rockers Evanescence, who delivered a soaring and captivating set that showcased the powerhouse vocals of singer Amy Lee. While the set wasn’t drastically different from the band’s last Bay Area gig, at SAP Center in San Jose, the Aftershock crowd brought extra exuberant energy that elevated the band’s sound to new heights.

Also different this time around was the addition of Sick Puppies bassist Emma Anzai, who aptly held down the low-end and seemingly made the bass more prominent. Anzai’s backing vocals matched Lee’s well and while the change may be subtle, it suits the band very well.

Evanescence leaned heavily on new material, taking most tracks from the stellar The Bitter Truth, but did mix in some older cuts along the way, including an orchestral version of “End of the Dream” and “Imaginary.” Lee’s vocals were absolutely captivating on both.

“Don’t let anyone speak for you,” Lee said before the anthemic “Use My Voice.”

Naturally, the group closed with its seminal hit “Bring Me to Life.”

Stone Temple Pilots

The transformation of Stone Temple Pilots vocalist Jeff Gutt is really quite staggering since the band’s last appearance at Aftershock. Gutt was the new guy; an impressive and charismatic vocalist with tendencies like former frontman Scott Weiland, even sounding like the late frontman. Over time, Gutt has grown more into the Weiland role, bringing more unpredictable spirit to the stage. The grunge heroes played a 10-song set that hit all STP’s greatest hits and performing them in fine form in the middle of the day.

“Hey Tyler, can you turn down the lights?” Gutt joked midway through the set, referencing the bright sun shining from the opposite end of the grounds.

Highlights included “Down,” “Interstate Love Song” and “Plush”

Killswitch Engage

Killswitch Engage offered up some of the heavier moments and best musical precision from day one, singer Jesse Leach’s growl emanated across the festival grounds. The band performed “My Curse” and “The End of Heartache” with added urgency. For as heavy as the material was, Leach often mixed in some jokes along the way.

“When this set is over I’m going to run into the forest and do mushrooms,” he joked.

Follow writer Mike DeWald at Twitter.com/mike_dewald.