Mary J Blige has a voice that was built to age gracefully. Gutsy, churchy, sometimes rough, it was miles away from the over-trained melismatics of the Mariah Carey and Whitney Houston imitators of the Nineties, or the velvet-toned ingenues that Aaliyah ushered in – and 25 years on from her debut album it certainly stands apart from the mannered Rihanna imitators of the current young generation.

A couple of years ago I saw an extraordinary outdoor concert where a rapper called Muslim (great name if you want to be hard to find on Google) performed at the Timitar Festival in Agadir in the South of Morocco to 80,000 delirious fans. The song which everyone knew was “Al Rissala" (The Letter) which called out corruption and ignorance in high places. The Festival acts as a kind of safety valve for dissent.

Oh BBC Four, we do love you, but this was an uncomfortable proposition from the start. We watch your pop music documentaries, because – let's face it – nobody else is making any, but so often they are pretty thin gruel. There are gems, of course, generally the ones focusing on an individual artist or label, or super-specific genre or time period. But the broad-sweep ones are more often than not a hodge-podge, seemingly governed in their narrative by what library footage was available, but also by a cripplingly old, white, rock establishment view of history.

De La Soul are the posterboys for creative longevity in hip hop. While some contemporaries have maintained a presence by relying on “heritage” status while going in ever-decreasing circles musically (hello, Public Enemy), the trio – still in their original line-up almost 30 years on – have never stood still. They've maintained strong relationships with the hip hop world, both underground and mainstream, while reaching out to interesting alternative collaborators (Yo La Tengo, Gorillaz etc) who've put them in front of new audiences.

The duo of Swae Lee and Slim Jxmmi – aka 21- and 23-year-old Tupelo Mississippi brothers Khalif and Aaquil Brown – are the epitome of everything that is baffling to ageing hip hop fans. Whisked from obscurity as teenagers by superstar producer Mike Will Made It, they became the breakthrough rap success of 2014, with what appeared to be little more than leaping around shirtless barking a bunch of half-nonsensical slogans and in-jokes about how much weed, money and sex they are surrounded by.

Around the turn of the millennium, two producers – the Californian Otis Jackson Jr aka Madlib, and the late James Yancey aka J Dilla from Detroit – started a revolution in hip hop: knocking beat patterns off the musical grid, searching further and wider than before for obscure and psychedelic sample sources, and generally making things weird and wonky.

A few beers down, in the middle of a crowd listening to music you love, you tend not to think of the latest news story as your highest priority. But Britain's relationship to Europe weighs heavy on the mind these days, and when the news of the violent attack on Jo Cox started filtering through as we danced under the Catalan sun on Thursday afternoon, it threw the nature of Sónar festival into relief.

In 2016, grime is facing a new test of its ability to operate on its own terms. At the start of this decade the genre was flirting with major label crossover that resulted in a few great pop records, but all too often diluted its musical impact or left its stars stuck in contractual or “artist development” limbo. Other urban genres pushed it aside, and it was no longer the only game in town for inner city youth.

Skepta (aka Joseph Adenuga Jr) and James Blake provide a fascinating parallel as voices of the UK's “generation bass”. Both are from north London, and both have come from a grounding in the subsonic undercurrents of London's early 21st century underground genres – Skepta mainly in grime, Blake in dubstep, although each reached into the other's scene a little via early collaborations – and both have risen to international success, in particular becoming influential on the American mainstream.