Mos Def is a living embodiment of the progress hip-hop has made since the late ’70s. Today the genre’s artists are no longer just masters of ceremony, but multi-faceted entertainers. In what now appears to be a one-time group effort, 1998 saw Mos Def and Talib Kweli bombard the hip-hop scene as Black Star with socially conscious lyrics about self-knowledge. Coupled with production by DJ Hi-Tek, the self-titled group album quickly placed both Def and Kweli in the spotlight as saviors from rap’s materialistic clichés.

While Kweli has gone on to record three albums in the past six years, Mos Def has drifted away from the microphone to make his presence felt in the acting world.

This time off from recording allowed fans to see him host Russell Simmons’ “Def Poetry,” perform on Broadway in “Topdog/Underdog,” and appear in feature films like “Monster’s Ball” and “Showtime.”

Def’s peak while away from the mic was this year’s performance in HBO’s Emmy-winning film, “Something the Lord Made,” in which his role as a black heart surgeon named Vivian Thomas was nominated for best actor in a miniseries Emmy.

It seemed that the general perception was one of Brooklyn’s favorites would never return for a solo album. But unbeknownst to many hip-hoppers, Mos had actually been working on music throughout his stint as an actor. Irritated with the nonexistence of black rock bands, Mos completely switched his style to form the rock/rap band, Black Jack Johnson. The group consists of Black pioneers of rock and funk, including members of Parliament Funkadelic, Living Colour and Bad Brains.

And while flashes of the old Def are still heard, the rapper could have saved his fans some trouble by labeling his latest album, “The New Danger,” as Black Jack’s debut.

Nonetheless, the rock ‘n’ roll influences of the album are not completely unwelcome. When Def and Johnson cleverly combine the sounds of the genres, the outcome is often powerful. “Ghetto Rock” serves as the introduction to Black Jack’s music of choice: a bass-heavy bounce with mesmerizing guitar licks. Much of the same is also heard on “Zimzallabim” and “The Easy Spell.”

Fortunately, Def does not leave those craving more bare-bones, rugged hip-hop beats stranded. Especially impressive is “The Rape Over,” a brief, clever reworking of Jay-Z’s “Takeover.” Except, Nas is not the subject of this diss record – the recording industry is.

Def’s version of Jay’s infamous chorus says it all: “Old white men is runnin’ this rap s—. Corporate forces runnin’ this rap s— … poke out our asses for a chance to cash in.”

Kanye West checks in to produce another highlight, “Sunshine,” which features West’s signature soul-sampled sound. Fans will also be pleased to hear “Close Edge,” which was featured in a Mos Def performance on “Chapelle’s Show.” Additionally, raw battle rhymes are found on “Grown Man Business,” featuring producer Minnesota and Mos trading verses over a Barry White sample.

However, the shining moment of this album has to be “Modern Marvel.” This nine-plus minute tribute to Marvin Gaye is a three-part opus that begins with Mos singing a capella before finally transforming into an inspiring rap over Gaye’s “Mercy Mercy Me (The Ecology).”

“When (Gaye) said, ‘Mercy, mercy,’ did he really know that decades later we’d still be killin’ folk,” says Mos, as he recaptures the same need for social change that Gaye did decades ago.

For those who were shocked to hear rappers like Outkast’s Andre 3000 and A Tribe Called Quest’s Q-Tip take on different musical styles, “The New Danger” may be worth passing by. Despite the variety of reactions this album will bring, Mos Def is determined to creatively push the boundaries of hip-hop and does so by way of a very interesting effort. For the listeners that understand that hip-hop no longer has a traditional sound, give “Danger” a try.