THE ROOTS' NEW album, "The Tipping Point," takes its name from Malcolm Gladwell's 2002 book, which is subtitled "How Little Things Can Make a Big Difference." Gladwell's thesis is that ideas, products and behaviors can spread like viruses and that the consequences of such social epidemics can ripple outward until a critical mass -- the tipping point -- is reached. Even a single person's behavior can affect society at large.

Case in point: The cover of the new album features a posterized photo of Malcolm Little -- aka pimp, drug dealer and gambler Detroit Red -- when he was arrested in 1946 on burglary charges. It was during the subsequent prison term that Little converted to Islam; taking the name Malcolm X, he would work tirelessly for social change from his release in 1952 until his assassination in 1965.

According to the Roots' extraordinary drummer, Ahmir "?uestlove" Thompson, that 1946 arrest was Little's personal tipping point -- "it's a critical moment in his life, where he left being Detroit Red to become Malcolm X" -- and ultimately a societal one as well, "a key moment in the revolution of the '60s."

While the Roots' ambitions for their new album may not be quite as epic, one senses they are both personal to the group and reflective of hip-hop in general. As MC and lyricist Black Thought (Tariq Trotter) notes in "Star," "Up against the clock and damn near outta time / The tippin' point has arrived and that's the bottom line / To all my peoples, the stars, it is our time to shine."

This is clearly a pivotal moment for a band committed to growth and innovation through a series of groundbreaking albums. More crucially, the Roots built their reputation through relentless touring and extraordinary live shows made all the more distinct by the fact that they were the first, and remain even now, hip-hop's only true band. The Roots -- whose core lineup includes bassist Leonard "Hub" Hubbard and keyboardist Kamal Gray -- don't use sequencers or DJs, though they've sometimes featured human beat boxes verbalizing turntable effects.

But while Black Thought's lyrics are full of DJ boasts, the Roots have never pushed gangsta fantasies or a bling-bling agenda. That's made them something of a hard sell to the hard-core rap constituency, where musicality is often less revered than beats and lyrics, but an easier one to jam fans and rock audiences, which tend to be more open to the group's musicianship. For instance, the tour that brings the Roots to Nissan Pavilion on Friday features jam rockers 311 and Agents of the Sun.

Which may be why in their 16-year existence, which includes a half-dozen acclaimed albums, the Roots have yet to enjoy platinum success.

"We have critical acclaim, but I don't think we've actually been forced down the throats of the public to a point where it's over-hyped and over-commercialized," says Thompson, adding that the Roots' golden reputation "has pretty much been word of mouth. We started selling a meager 10,000 units of our first album [1993's "Organix"] and went to 900,000 [1999's "Things Fall Apart"]."

Does that suggest a sense of frustration, or perhaps impatience, reflected in the new album's title?

With a chuckle, Thompson says, "it was either naming it 'The Tipping Point' or 'The Tortoise and the Hare.' "

Thompson admits that the Roots don't always make it easy on themselves.

"There are people who are absolutely in love with our idea of pure hip-hop, so they champion us for that but they can't stand the musicianship of the group," he says. "There are some people that just love the live experience of the Roots but they don't get into our records that much. There are some people that love the production but think that our live shows are . . . whatever."

Certainly the Roots don't repeat themselves. Their breakthrough album, 1996's "illadelph halflife," captured the dynamic tension of their live shows without abandoning an adventurous underground aesthetic. But its follow-up, "Things Fall Apart," was built around looser grooves that helped usher in the neo-soul movement and gave the Roots their only "hit," the Jill Scott-penned, Erykah Badu-vocalized "You Got Me." After a quick fan-fix via a live release, "The Roots Come Alive," the Roots changed their game again with 2001's "Phrenology," which was faster, louder, more aggressive and far more ambitious and experimental in its soul/rock approach (the guitar player on that album, Ben Kenny, is now with Incubus).

By contrast, "The Tipping Point" scales back the experimentation in favor of hip-hop fundamentals -- the Roots going back to their roots. As in the very early days, basic tracks were born out of jam sessions.

"The challenge for us with 'Phrenology' was to make a record that was the anti-Roots record: Everything that we're not supposed to do, let's do," Thompson explains. "Let's do the R&B song, let's do the rock song, let's do the punk song, the sprawling jazz song, the electronica song, the techno song. We did everything that we were not supposed to do -- which was easier because that's us on the real.

"The hardest thing was to make a short, concise, get-to-the-point, cut-the-fat record."

That's why many of the special guests who tumbled through "Tipping Point" sessions ended up on the cutting-room floor. It's also why the Roots are getting their best reviews in a long time from the sometimes indifferent hip-hop press, which has proclaimed the Roots "back."

Thompson finds that funny.

"I never knew we left," he says, recalling listening parties for various hip-hop magazines before the album's release.

"I loved the shock on their faces, especially in the age of [OutKast's multi-platinum, Grammy-dominating] 'The Love Below.' I think they thought I was going to try to outdo Andre, but I think the only way to react to 'The Love Below' is to make a shockingly normal record."

For instance, "Star" samples Sly and the Family Stone's 1970 song "Everybody Is a Star," with Black Thought's lyrics recasting it as a cautionary narrative around celebrity and the glorification of criminal culture. Thompson has said that a fan approached him in a supermarket claiming to have had a vision of the Roots' covering that song and that soon after, the band was asked to contribute to "Sly2K," a remix/tribute album. It features Beck, Moby, Lenny Kravitz, Floetry, Maroon 5 and Black Eyed Peas, and will be released next year.

Thompson, originally hoping for another Sly standard, admits he wasn't expecting anything great to happen with that particular song. "I really wanted to get my hands on my personal favorites of Sly . . . but 'Star' started taking on a life of its own and with Tariq, I didn't know what direction he was going to take it."

Which, on several songs, was a more political direction. On "Guns Are Drawn," Black Thought addresses the emergence of the right, the Patriot Act and the police state, the war in Iraq and the rush for oil, while "Why (What's Going On?)" echoes the social consciousness of its Marvin Gaye reference.

Thompson says, "Even though we've touched on some political concepts, we've never been on a soapbox or really preached down to people. It's never been a group discussion because usually the music gets made first, and Black Thought just writes the lyrics on his own somewhere secluded -- it's sort of like Moses comes back from the mountain with the tablets in his hands. I guess we were just expecting the same standard MC fare that we've been getting for 12 years."

But, Thompson adds, "He is a father of two now and, on top of that, he's a big-brother mentor to Mac Dub [16-year-old Floyd 'Sonny' Carson], one of the MCs on 'Somebody's Gotta Do It.' Mac's been idolizing Tariq since the age of 6 -- they share the same barber -- and our 'illadelph halflife' is the first and only CD that Mac has ever owned. Mac is growing up and he'd been in a lot of trouble between 10 and 14, and Tariq stepped up his role in his life because he doesn't want to see potential go to waste.

"If anything, a lot of these songs are sort of letters written to Mac. If you listen to 'Star' and 'Don't Say Nuthin',' and try to envision who Tariq is talking to, I really think he's talking to Mac. They're cautionary tales: I've been there and I see you're headed for trouble and this is my warning."

It's not that the new album is overly sober. Even "Don't Say Nuthin' " mimics gangsta grooves and cliches while featuring a mumbled chorus Flavor Flav would be proud of. "Web" is a highly syncopated duet between ?uestlove and Black Thought, a flashback to 1987, when they first met at Philadelphia's High School for the Creative and Performing Arts and, unable to afford such DJ essentials as turntables, records or microphones, opted to jam on drum kit and notebooks alone. There are old-school homages -- "Web" name-checks a gallery of hip-hop heroes and heroines, and on "Boom!" Black Thought lovingly impersonates Big Daddy Kane and Kool G Rap -- while a hidden track, "In Love With the Mic," features comic Dave Chappelle. Thompson is the music supervisor for Comedy Central's "Chappelle's Show"; a celebrity DJ, he'll be spinning records late Friday night at the Black Cat.

Speaking of hidden tracks, "The Tipping Point" has two, though lucky Brits will find three on their version of the CD. The other common track is "Din Daa Daa," a percussive workout by Thompson on George Kranz's early '80s club smash, "Trommeltanz (Din Daa Daa)." The Brits also get an 11-minute version of Booker T. and the MGs' "Melting Pot," suggested by DJ Gilles Peterson, who was one of the first to champion the Roots.

"He thought it was utterly ridiculous that we were such a live funky band and had never displayed this on wax," Thompson says. "He said, 'How can you be a band and not have your own 'Pick Up the Pieces'? You've never done a drum break, you've never given the drummer something! You guys have become a band to replace samples, but you haven't got it on record!'

"So we went into the studio and covered 'Melting Pot.' It was fun, and it sounds very dirty and liberating. We mixed it that night, brought it to [influential New York radio DJs] Rich Medina and Bobbito Garcia, and they were so excited: 'Can you believe it, it's the Roots with a drum break!' I got over-excited and went back the next day and did 'Din Daa Daa.' " Actually, we did eight more, so I might be flirting with the idea of actually doing a Roots instrumental album."

THE ROOTS -- Appearing Friday at Nissan Pavilion with 311 and Agents of the Sun. * To hear a free Sound Bite from the Roots, call Post-Haste at 301-313-2200 and press 8121. (Prince William residents, call 703-690-4110.)

On their new album, "The Tipping Point," the Roots -- Kamal Gray, from left, Black Thought, Ahmir "?uestlove" Thompson and Leonard "Hub" Hubbard -- eschew experimental approaches and return to hip-hop fundamentals.