On the third night of Converse’s Rubber Tracks series, fans were treated to a free show of pulsating reverb from Slayer providing a jolt to the audience that served as a reality check reminding the crowd they were one of the lucky fans getting to bask in the glory of these metal gods, for free, in an intimate venue.

Local metal men Rozamov, fresh off the release of their split with Death Kings, included their new single “Ghost Divine,” to start off the evening with fast, heavy shred, owning the stage with the aggression of a trio of hungry wolves spotting a wounded fawn. They brought a powerful presence, undoubtedly influenced by the masters ahead of them in the evening, and their brief set got people gritting their teeth and ready for the main course to come.

Doomriders emerged to continue the berating. These Bostonians live on nearby hardcore label Deathwish Records, and growled into the mics while dodging swinging guitars. They raised the bar so high that any band other than Slayer might have struggled to emerge as the true headliner afterward.

But as Slayer took the stage, their admirable collection of beards on full display, it was clear to everyone that we were in the midst of guitar gurus. While goading fans with raised hands before a guitar solo, lead singer Tom Araya asked, “What is this? Are you studying to be a surgeon?” and seemed very upbeat (even smiling!) in spite of their doom and gloom professional veneer. As one of the loudest bands I’ve ever seen, ecstatic fans were holding their ears from time to time to keep them from bleeding. It was near-spiritual in its own way, and as they closed on their 1986 classic “Angel of Death” from Reign in Blood guitarists Kerry King and Gary Holt shredded mercilessly and with soul-crushing accuracy.

Along with two openers from Boston, and providing a few lucky hundred folks with intimate music memories, Converse is giving back to the Boston community in a big way with this free series of incredible live music. When it’s all said and done, one can only hope this will inspire a new trend of incredible gratis concerts being gifted an ever-grateful public. After all, if there’s one thing the people behind the classic Chuck Taylor design know, it’s how to start something big.