Fifteen years go by in the blink of an eye. It's that long since Mos Def's debut album appeared. The Brooklyn rapper was no naive tyro – he'd released the well-received Black Star collaboration with Talib Kweli the previous year. But Black on Both Sides was where Mos Def struck out for the higher ground.

Today, that record reminds you of a different time in hip-hop. It encapsulates much of what was going on in the 1990s.

For a start, it was released on Rawkus, the label set up by Brian Brater and Jarret Myer with cash investment from James Murdoch (yes, that Murdoch clan). At the time, Rawkus was king of the walk, the imprint that provided an imprimatur for much of New York's underground hip-hop scene thank to releases such as Company Flow's Funcrusher Plus and the Lyricist Lounge series. It was a label with serious game.

For the man born Dante Terrell Smith, the label was his launchpad. Mos Def grew up in Brooklyn and watched classmates make thousands of dollars from hustling crack and avoiding the attentions of street gangs. After dropping out of school, he got caught up in what the various artistic crews and collectives were doing in downtown Manhattan.

While acting was on his radar even then (he appeared in The Cosby Mysteries alongside Bill Cosby), Mos Def also wanted to grab the microphone. Inspired by authors Chinua Achebe and Chester Himes, and early tracks by Common, he and his siblings started up the Urban Thermo Dynamics group and signed to Payday.

"We was like a hood version of the Fugees," he said of this family affair at a later stage. But despite production help from Showbiz and AG and Diamond D, Killing Me Softly-like fame eluded them.

Enter Rawkus and Kweli, the label and the collaborator who put him on the right path. The Black Star album was a one-off, but it set a mood. Here was a pair of astute, sharp and erudite kids diving into the hip-hop culture's deeper issues at a time when many of their peers were simply mouthing off about much more materialistic concerns.

Black on Both Sides came fast on its heels. It was expansive and invigorating, the work of an artist keen to muse on the global and local issues from ecology to religion and via the culture he'd seen on the streets as he grew up.

From the get-go, Mos Def swung and swaggered with a difference. His debut was on-point and timeless, with a sound (jazzy and trippy, hazy synths, wonky beats) and a message (fiery, passionate, politically aware) that were remarkably fully formed. He was the real deal.

Major leap

In the years after Black on Both Sides, Mos Def jumped to the major label world, but it took him a good few years to reach the heights of his debut. Arguably, it wasn't until 2009 that the rapper rediscovered the spark. On The Ecstatic, Mos Def sounded dynamic and switched on, a rapper with an eye once again on the bigger picture.

In recent years, Mos Def has become better known for his activism than anything he’s done on screen or in studio. In 2013, the rapper (by then known as Yasiin Bey) appeared in a video for human-rights group Reprieve, where he underwent the same force-feeding experienced by hunger strikers in the Guantanamo Bay detention camp.

Last year also saw him move to Cape Town because he felt things were “not so good with America” and he had some scathing things to say about US foreign policy.

“America should deal with cleaning up its own house,” he said, “and stop fucking with people, and stop pursuing its international interests with such disregard for how these people live, their cultural ties. It’s some crazy colonial invader.”

The live shows, though sporadic of late (some US gigs have been cancelled due to “immigration and legal issues”), are widely acclaimed . You get a mix of the classics and recent material, all with a sense that Mos Def himself is the only one who knows where the show is heading.

Given his past, that’s a steer many are prepared to follow.