Headbangers, metalheads and curious onlookers comprising the San Antonio chapter of the Black Label Society on Friday night at the Boeing Center at Tech Port may not have realized they were watching a riddle unfold before their eyes.

Three bands on stage. Two of them had four members each, while the other utilized three. But there were only seven musicians combined.

Since when does 4 + 4 + 3 = 7?

That’s what you get when BLS, Zakk Sabbath and Dark Chapel come together.

BLS, in its 28th year as the brainchild of guitarist / vocalist Zakk Wylde, was making its first appearance at the Boeing Center since being the middle band Feb. 10, 2023, in support of Anthrax with opening act Exodus.

This time, Wylde’s band comprised of bassist John “J.D.” DeServio, drummer Jeff Fabb and guitarist Dario Lorina were headlining joined by, well, the trio of Wylde, DeServio and Fabb known as Zakk Sabbath.

Not to be outdone in the double duty department was Lorina, who unleashed his bluesy vocal skills to go with lead guitar as the frontman of Las Vegas-based Dark Chapel, which kicked off the night in support of their 2025 debut Spirit in the Glass.

But the Alamo City chapter didn’t come to the Boeing for a math lesson or to solve riddles. They came to rock. And the bands took care of that with ease.

BLS was fully charged in support of Engines of Demolition, performing a 12-song set in 1 hour, 24-minutes.

Focusing on half of their 12 studio albums going back to 2003’s The Blessed Hellride, Black Label Society mixed in older tunes such as “Funeral Bell” and “Suicide Messiah” with new-album track “Name In Blood” — though they omitted anything from 2010 personal favorite Order of the Black.

Wylde, who entered heavy metal’s conscience as a precocious 19-year-old on an episode of MTV’s “Headbangers Ball” after being hired as Ozzy Osbourne’s guitarist, has made a habit of dedicating part of his visits to honoring the late Pantera guitarist “Dimebag” Darrell Abbott and now Abbott’s late brother, drummer Vinnie Paul.

But of course, this latest BLS concert hit home even more after Osbourne passed last year.

To his credit, Wylde didn’t stack the emotional waterworks on top of one another. After his traditional piano-led “In This River” tribute to the Pantera brothers, BLS returned to the heaviness with “The Blessed Hellride,” “Set You Free” and “Fire It Up.” The latter saw Wylde stand atop the piano and blister into his solo with the guitar behind his head while Lorina did the same several feet away before Wylde tossed in a brief “Smoke on the Water” riff to end it.

“Ozzy’s Song” from the latest album was of course mandatory, and Lorina sat behind the piano for that one while Wylde provided his vocals and guitar work. A triplet of classic Osbourne photos dotted the big screen but, surprisingly, they were the only pictures of the Ozzman shown throughout the evening. Just as unexpected was the fact that unlike his previous visit, Wylde left himself out of the photos shown of Abbott and Paul.

Wylde also broke up “Heart of Darkness” with the “No More Tears” solo and sang its final verse. But there was arguably no larger tribute to Osbourne than the fact Wylde formed Zakk Sabbath in 2014 and has had headlining tours with that band.

This time, Wylde, Fabb and DeServio directly supported themselves, challenging their conditioning, stamina and vocal health each night.

As the middle artist Friday, Zakk Sabbath limited itself to five songs (setlist below; no professional video was allowed), but still turned it into a 49-minute set. The highlight came during finale “War Pigs” when Wylde left the stage and was escorted to the front of the soundboard, ripping into a lengthy guitar solo behind half of the general-admission portion of the crowd that was still staring at the front of the stage unaware of the presence and sound emanating behind them (see 85-photo gallery).

Fabb, the original drummer for In This Moment when that band formed 20 years ago, utilized two different kits for each band. His Zakk Sabbath setup included one bass drum while his BLS machinery had two.

Dark Chapel got the festivities started in a heavy yet bluesy way with Lorina, rhythm guitarist Dylan Dyce, bassist Mike Leon and drummer Jeremiah Walker spotlighting their album but also pulling off a cover of Bill Withers’ 1971 classic “Ain’t No Sunshine.”

Leon was his usual animalistic self on stage after spending the past several years in Soulfly and Cavalera Conspiracy with former Sepultura voice Max Cavalera.

While the crowd of 2,000 — according to a LIve Nation staffer — in the 3,000-capacity Boeing Center got their money’s worth and appeared to thoroughly enjoy themselves, a pair of fans received an extra dose of reality when Wylde ended everyone’s night by wiping his sweaty forehead with two washcloths and tossing them into the crowd. Wylde had definitely earned a cooldown moment. As did his double-duty bandmates.

Their engines of riffage remained ringing in these ears throughout the drive home. And the legends watching from above probably would’ve taken that as the greatest tribute of them all.