The aging hippies, toddlers in face paint, and crunchy college students gathered in Davis Square for the ArtBeat festival look better suited to a Greenpeace rally than a hip-hop show. Nevertheless, when Mr. Lif takes the stage, they’re treated to a set of gritty, strident, uncompromising underground hip-hop, whether they like it or not. Fortunately, they do like it.

As the final ArtBeat act, Lif faces a thinning crowd when he launches into his set by asking, "Party people in the place to be, how y’all feelin’?" The lethargic answer is less than overwhelming. An hour later, when he closes with an a cappella version of his political screed "Home of the Brave," a dense mass of dancers has crowded near the front of the stage, little kids are clapping in time, and a roar of applause rises up from the audience. After the show, the love fest continues. Family and friends, including his mom, are waiting for face time, but he spends more than 30 minutes selling CDs, signing autographs, posing for photos, and listening to cringe-worthy rhymes from eager MCs.

Whether performing for hip-hop heads at the Middle East, opening for non-rap acts like Burning Spear and Tortoise, or playing for a multi-generational crowd at ArtBeat, Lif has managed to transform the prickly nature of independent hip-hop into an accessible, all-ages blast that appeals to pretty much anyone. That’s partly a reflection of his willingness to cater to each audience. At ArtBeat, he performs his "Hip-Hop 101" set, explaining rap basics like freestyling and self-editing the swear words out of every song: "shit" becomes "isht," and "fuck" becomes "e-ff." But it’s the music itself — a blend of personal reflection and political venting, sci-fi imagery and b-boy boasts, heady philosophizing and goofy skits — and his self-depreciating stage presence that really wins over the crowd. Or as his mom points out: "He’s just so lovable, and I swear that’s not just because I’m his mother. How could you not like him?"

That’s a common opinion these days, as Lif seems poised to make a national breakthrough. After five years of assorted singles and EPs, he released his first full-length album, I Phantom (Definitive Jux), at the beginning of this month. It concludes what’s been a very busy year. He spent most of the winter and spring in the studio, then toured with El-P to support his friend’s recent Fantastic Damage disc. In June he released the Emergency Rations EP (Definitive Jux); in July he went on the road with DJ Shadow; and he spent August touring through Japan and Australia with members of the Definitive Jux crew.

All that work seems to being paying off. Emergency Rations sold more than 3000 copies in its first week. More important, I Phantom has already picked up glowing reviews in the Source, Vibe, and, strangely enough, the New York Times. In short, this new release isn’t just the great Lif album that his Boston fans have eagerly awaited — it’s a disc that the rest of the country seems to be yearning for as well.

I Phantom is also a concept album. "Yeah, I don’t like that term," he admits when we sit down to talk in Davis Square after the crowd of admirers has dispersed. "But I wanted to make a real album, not just a collection of jams. I grew up in the era of De La Soul’s Three Feet High and Rising and Public Enemy’s It Takes a Nation of Millions To Hold Us Back, when records had an overall feel and took you somewhere."

I Phantom definitely takes you somewhere, but it’s not always a pleasant place to be — the disc begins with a gunshot and ends with a nuclear blast. Emergency Rations had a political slant; I Phantom finds Lif turning his sharp insight inward, looking at how the pressures of work, school, and social life lead to emotional alienation and personal decay. He explains, "The album is about the various problems and ills in our society and how they cause decay within all of us." That may sound a bit term-paperish, but he turns the heady subject matter into a series of narratives, rants, and fables that are by turns hilarious, remorseful, and gripping.

Lif’s dark sense of humor infects "Live from the Plantation," an anti-work screed that lies somewhere between De La Soul’s "Bitties in the BK Lounge" and Office Space. Except that Lif’s 9-to-5 ends with a murder: "Dead boss/Somebody call Red Cross/I guess he got caught up in my mental holocaust." Most of the record comes off like a hip-hop American Beauty: it’s filled with the creeping rot of neglectful dads, distant daughters, and hollow materialism. Weaving the various characters together in a style that is half comic strip and half Robert Altman, Lif takes on the voice of his dumped-on characters as they struggle through divorce ("The Now"), work ("Success"), and social striving ("Status").

He’s not the only MC digging into family matters these days. Alongside the matricidal rants of Eminem and the self-loathing relationship rap of Minneapolis’s Atmosphere, I Phantom fits squarely into the new sensitive-thug emo-rap landscape. "I think we’re in an age of artists who are fairly introspective. There’s a lot of this self-cleansing hip-hop. I think it’s because you have a bunch of artists who are in their mid 20s. We have some perspective now, and we’re trying to figure out who the fuck we are!"

Nevertheless, Lif seems to be doing a pretty good job of navigating his 20s. He recently moved out to Berkeley to live with his long-time girlfriend, so he spends a lot of time shuttling among the Bay Area, Boston, and Brooklyn, where he records most of his music. But he hasn’t adopted a West Coast identity: "I can’t lose my Boston-ness, man! I’ve lived here for 26 years, the Pats just won the Super Bowl, the Celts and Bruins were in the playoffs. You can’t ever shake the Boston-ness!"

All the same, his bi-coastal existence has taken its toll. "I tell you what, I bitch about it, but I shouldn’t. It’s a lot of hard work, man. My life is moving at a blinding pace. I don’t like being away from my lady, and when I’m away from my parents for a while, I get on edge. It’s a challenge to maintain a personal life." But the positives outweigh the negatives. "I really like the energy of it all. Every artist wants to be seen or heard, and I’m getting the opportunity to communicate with more people. Just as a lover of hip-hop, I’m seeing this whole new era come up — Edan, El-P, and the whole Definitive Jux crew, it’s like a new movement, and I feel like I’m part of something. That fills me with so much determination. I want to give kids an era like I had back in the day with A Tribe Called Quest and Public Enemy. I want kids to be happy and excited when my shit comes out: that’s hip-hop. That intangible fire that is the music, I love being part of it."

CAMBRIDGE RHYME PHENOM Virtuoso returns to shelves with the "God of Thunder" (Omnipotent Records) 12-inch, his first release since the last year’s full-length World War One: The Voice of Reason. Produced by Chicago’s Moleman, "God of Thunder" is the kind of larger-than-life track that fans have come to expect, with plenty of fantastical flourishes for Lord of the Rings fans. Flowing swiftly over rumbles of thunder and cracks of lightning, Virtuoso sounds stuck somewhere between Dungeons & Dragons and the Wu-Tang Clan — and that’s a good thing. The title of the B-side, "Smashtapiece Theater," pretty much explains what you need to know; it sports vicious battle rhymes over a beat that would make Wagner smile.

Virtuoso isn’t just rhyming these days, he’s also helping to run an independent label, Omnipotent Records. This summer Omnipotent stepped up its output with a handful of solid releases, including 12-inchers from New York underground fave C-Rayz Walz and Philadelphia mike controller Jus Allah (formerly of Jedi Mind Tricks). The most interesting release, however, was the Motherbrain EP by local MC Bomshot. "We highly recommend installing a synthetic pacemaker for proper analysis of these recordings," suggests the accompanying press release. Uh, okay. Maybe not, but a fondness for left-of-center MCs like Kool Keith and Sensational might be a prerequisite for Bomshot, who’s fond of spitting bizarre interstellar rhymes and mathematical/scientifical non-sequiturs over lo-fi beats that sputter and hiss like a water-logged mainframe. "Commence analysis electrolysis and dialysis/Puncture his epidermis/Reconstructed rectum’s how I showed him/Take your scrotum down low and log onto the modem," he blurts on "Space Cadet." Party jams they’re not, but if MIT is looking for a themesong, Bomshot should get the call.