On December 12, 2000, Los Angeles, California-based MC Xzibit dropped his third album, one that arrived at a curious juncture in his musical and professional careers. Already considered a West Coast favorite thanks to the grassroots and Underground support of his sophomore effort 40 Dayz & 40 Nightz, the streets were ready for a strong follow-up, and fans were not disappointed. Restless featured big-body production from Dr. Dre, DJ Quik, Eminem, Rockwilder, Erick Sermon, and others and it stands today as his only platinum-selling album. By that measure, it represents the apex of his Rap career, but it came a full two years before his mainstream fame really took off. His 2003-2007 stint as host of MTV’s “Pimp My Ride” introduced him to audiences outside of Hip-Hop, and he became one of the most visible celebrities from the Rap world in popular culture of the mid aughts. And so, by that measure, Restless also marked the slowing pace in success he faced on the charts. Although 2002’s Man vs. Machine debuted in the #3 position, it was a relatively short stint and X to the Z struggled to reclaim the momentum he had achieved with Restless. Nevertheless, it is undoubtedly forever ingrained in the fabric and soundtrack of the new millennium, and 15 years later, it still knocks.

Restless was X’s re-introduction in many ways. After debuting with 1996’s At the Speed of Life, the Detroit, Michigan-to-Albuquerque, New Mexico-to-L.A. MC began enjoying the fruits of the labor as a result of the groundwork he was laying in the L.A. Rap scene, forming relationships with area legends like King T, DJ Muggs, and, most famously, Tha Alkaholiks. It wasn’t until Restless, however, that Xzibit was a cohort and collaborator of Dr. Dre, the undisputed king of Los Angeles Rap who had showcased X on his 1999 juggernaut, 2001 (on “Lolo,” “What’s the Difference,” and “Some L.A. Niggaz”). X fans already respected his skills as a lyricist and purveyor of the newest generation of street knowledge, but the Dr. Dre co-sign elevated him from Underground Hip-Hop standout to national recognition. However, he had always enjoyed a healthy international fan base, even from the very beginning of his career. His lead single, 1996’s “Paparazzi,” scored a meager #86 position on U.S. charts but in Germany, it was a smash hit, nearly cracking the Top 10 but resting at a very #11. Similarly, Restless’ “X” was the most successful of the album’s three singles, but it outperformed the U.S. all over Europe, shooting to number four amongst his German fans. That is not to say he didn’t enjoy his fair share of admiration from stateside fans; the album eventually made its way into the #12 position on the U.S. charts, and the album’s success played a huge role in X’s being invited to take part in Dr. Dre’s hugely successful Up In Smoke Tour, a West Coast mammoth of a tour that became a cultural phenom.

In addition to “X,” the branding anthem whose accompanying video featured cameos from West Coast legends Snoop Dogg as well as surprise appearances from Loud Records affiliates RZA and Method Man, Restless spawned the singles “Front 2 Back” and “Get Your Walk On.” The former was a monster amp-up lead single built atop Rockwilder’s East Coast sensibilities marching forcefully, a perfect match for X’s high-energy delivery. The latter was a distinctly Los Angeles affair, an homage to the Crip Walk akin to Kurupt’s 1998 album cut “C Walk.” Xzibit’s version was louder and less specific to the dance’s ties to gangs, and despite the video’s featuring X and others performing the dance, it is remembered outside of the realm of Gangsta Rap. In fact, the video includes a segment featuring the blue and red colors signifying the Crips & Bloods, the notorious rival street gangs who have made Los Angeles the infamous home of rag-warfare. In his including such an image, it’s clear the song was meant to appeal to a national audience, and is (intentionally or not) adulterated to reflect that sensibility. But don’t get it twisted…the co-production from Battlecat and Dre under-study Mel-Man is far from watered down, and still manages to elicit rousing responses on dance-floors. In all, the three singles anchoring Restless were clear markers of the era; big, loud, flashy, aggressive.

“Been a Long Time” featuring Nate Dogg provided some serious bounce to the LP, the Erick Sermon, J-Ro and Tash-assisted “Alkaholik” is one of the most celebrated cuts and would have been a single if it were not for the radio censors. While there were predictable – but nonetheless great – appearances from Eminem (“Don’t Approach Me”), Snoop Dogg (“D.N.A.”), DJ Quik and Suga Free (“Sorry I’m Away So Much”), and Dr. Dre (“U Know”), the album’s most overlooked cut is “Kenny Parker Show 2001,” featuring the one and only KRS-One and familial DJ. The Teacha provides a hook and some knowledge, but pairing of the two over a Dre knocker is a simple but powerful marriage of the forefather and the Prince, who KRS calls the “ultimate, underground rawness,” an accolade not to be taken lightly coming from such an iconic source.

Above all else, Xzibit stands tall as an integral figure in Rap’s mainstream appeal at the top of the first decade of the 21st century, and despite not having yet besting the sales of Restless, his fans know that true credit and real appreciation is often not reflected by the constraints of numbers and dollar signs. His contributions to the visibility of Rap into mainstream TV is not an accomplishment to be brushed over, and his continued adoration overseas and back home are indicative of the loyalty in the fan-base he’s been cultivating for two decades. After taking a hiatus from his solo career from 2006-2012, his recent reemergence on the scene has spurred talk of his 2016 return, and X may be poised for a strong comeback. He has reunited with Dr. Dre, appearing on Compton‘s “Loose Cannons,” and his mention of a solo album planned for next year during recent performances seem to confirm their reunion will play a role in his forthcoming eight solo effort. In the meantime, fans can hear his work with the Serial Killers, the trio he formed with Cypress Hill’s B-Real and Demrick, a longtime collaborator of X’s.

In the careers of great MCs, there is often a pinpointed moment when they pivot from underground to household name. Fresh off of transforming Eminem from a 12″ single sensation to a superstar with “Stan’s” in tow, Dr. Dre eyed up another Motown native. Xzibit had fashioned a respected career up to year 2000, dropping stellar freestyles, making lauded Loud Records albums, and running with King T, Defari, Phil Da Agony, and Lootpack as the loosely-defined Likwit Crew. However, Restless was the moment the well-kept secret (at least in the States) went viral. The raspy-voiced, beer-breathed MC with the wit, charm, and raucous delivery stood tall. Suddenly, Xzibit was somebody to the paparazzi. The back-packing MC made the album he likely fantasized of making, and in turn, blazed paved a lamp-lit road into the next 15 years. His career has been restless ever since.

Related: Take A Journey With The Serial Killers, Better Known As B-Real, Xzibit & Demrick (Video)