According to Dilated Peoples, “all movements begin underground.” It’s their informal motto, referring both to their status in the industry and the earthiness of their music. When the Los Angeles trio formed in 1997, they presented themselves as hip-hop fundamentalists of the old-school variety, and they haven’t wavered in the intervening years.

On their first LP, The Platform, they revived the idea of hip-hop as a sort of musical construction project, a cultural edifice rooted in the urban community. By wrestling the hyper-aestheticized, hyper-commercialized genre of “rap” back down to its essentials (those would be beats and lyrics, Mr. Durst), they’ve helped rebuild the often-patchy West Coast underground scene on a foundation of widespread street-level support.

And for an underground group, the support sure is widespread. In the months following the release of The Platform, I would actually hear Californians inexplicably scream out “Dilated!” at random, non-musical events.

On Tuesday night, The Dilated Expansion Team Tour landed at Toad’s Place and gave ample demonstration of why (and how) they’ve achieved what they have. Emcees Rakaa and Evidence trampled on stage to the thudding bassline of “Clockwork,” their new DJ Premier-produced track, then proceeded to propel severe, content-heavy verses over the crowd with flair and coarse agility.

DJ Babu (of the Beat Junkies) cut and scratched his way through chorus after chorus, fitting expressive, perfectly executed rhythms into the basic texture of kick and snare. What sets Babu apart from his turntable colleagues is his self-restraint. His intuitive feel for songcraft allows him to weave breathtaking, lightning-fast scratch flourishes around the beat with plenty of empty space for bass notes and punchlines.

Nut Rakaa and Evidence weren’t at all overshadowed. They traded lines and half-lines a la Run DMC, grimaced their way through blistering versions of “Panic” and “No Surrender,” and happily rattled off the sci-fi nonsense of “Triple Optics.” As DJ Babu began to beat juggle (manipulating the same instrumental on two turntables to produce a new breakbeat) during his solo, Evidence shook his head, saying “Watch out” and dancing along.

The diversity of Dilated Peoples is a tacit manifestation of their positive social message. The group and their fan base reflect the ethnic mixture inherent in hip-hop communities — not to mention the integration of different artistic forms. Babu is the Asian turntablist, Rakaa the African-American emcee, Evidence the light-skinned graffiti artist. The only hip-hop element missing is a breakdancer, but Tuesday’s crowd supplied the necessary physical energy.

To that end, the group has tried to keep their art as close as possible to the hip-hop community. With respect and consideration to aspiring DJs and the ideology of “indie music,” the group crafted their major label contract such that they would retain all rights and control over vinyl production. That’s why they play clubs like Toad’s instead of hitting larger venues when touring the East Coast.

Two highlights of the show: an a cappella version of Rakaa’s poem “War” accompanied by audience hand-claps, and a thunderous tear through Dilated signature tune, “Work the Angles,” during which Evidence spurred the crowd to “jump so hard we skip the record.” As the building shook and the emcees rushed to grab as many hands as they could, one thing became clear: whether or not it’s happening underground, the Dilated movement is reaching the people.