SAN FRANCISCO — Eighteen years ago, when Thursday appeared, punk and hardcore music was in a weird place. Bands like Blink-182 and Jimmy Eat World played TRL, Glassjaw signed to Roadrunner Records and East Coast bands like Brand New and Saves The Day were making the rawness of emo more accessible.

Thursday

Vein

8 p.m., Friday

Great American Music Hall

Tickets: $35-$60.

Thursday’s sing-scream dynamic, its intensity and ability to embrace the quiet moments and when to hit the throttle were a blueprint for the emerging post-hardcore genre that was slowly becoming a commercial success. The band served as an archetype for numerous emo and complex hardcore acts that followed, including Touché Amoré, Circa Survive, Silverstein and La Dispute.

So when Thursday’s iconic frontman, Geoff Rickly, stepped onstage at The Great American Music Hall on Thursday to bring 2001 sophomore album Full Collapse to a sea of screaming fans, he found himself facing those who resonated with his music all these years back.

The band members grinned ear to ear and were ready to kick off the first night of their tour playing Full Collapse and War All The Time for two nights in a row. Thursday started with the ambient “A0001” and then launched into an intense rendition of “Understanding in a Car Crash,” the first song on Full Collapse. Rickly was no longer the kid bearing his soul to a youthful audience. But age in only a number in punk rock, and as soon as the music kicked in, he began singing with the intensity of those he influenced, commanding the stage and performing with strict intent and loose glee.

Thursday proceeded to play Full Collapse in its entirety, blazing through “Concealer” and “Autobiography of a Nation” in a seamless barrage of frantic chords. It didn’t take long for the audience of 30-somethings to explode into a mosh pit that felt more like a cathartic and communal outbreak rather than a violent display of aggression. During “Standing on the Edge of Summer,” the band showed off its ability to tear at the seams of traditional post-hardcore and find a sound somewhere between Snapcase and American Football. This sound has garnered fans that might not have felt like they belonged to a certain genre.

The album’s final track, “How Long is the Night?” was a song drenched in tragedy. It brought down the house with its lyrical imagery with lines like “What are we gonna do?/ The trees are giving up on us” and “I will never sleep again/ I will never even close my eyes.” Eventually the song crossfaded into the mirrored and haunting closing track “I1100.”

Rickly and crew then played some other Thursday cuts, including “Turnpike Divides” from 2011’s No Devolución, “Counting 5-4-3-2-1” from 2006’s A City by the Light Divided and the visceral “Jet Black New Year,” a song that released an explosion of confetti.

The “full albums” tour will continue tonight when the band tackles 2003’s War All The Time, the album on which the band polished its signature sound.

Thursday’s bill kicked off with much-hyped Boston’s metal and hardcore band Vein turning in an energetic performance of groove-based and impressively technical metal. The band conjured the power of early Converge while lead singer Anthony DiDio growled and bellowed songs like “Progenitor”and the impressive “Doomtech” (the latter from 2018’s Errorzone).

Guitarists Jeremy Martin and Josh Butts engaged in Dillinger-Escape-Plan-like barrage of visceral sound as drummer Matt Wood and bassist Jon Lhaubouet slammed away behind them. Vein is without a doubt the bright future of uncompromising hardcore.

Follow photographer Shawn Robbins at Instagram.com/photo_robbins and Twitter.com/ShawnTheRobbins.