In 1991, the Basque performance artist Esther Ferrar wrote a letter to modern music’s inventive genius, John Cage, on the future of anarchism.

At the beginning of last night's show, Herbie Hancock looked like he was going to perform with the dignity and serenity befitting a 72-year-old with some 50 years playing experience. The improvisation that launched from a base of Wayne Shorter's “Footprints” was elegant, charming, tasteful and often very beautiful. The synthetic instrumental loops that he triggered via a couple of iPads mounted on his grand piano as backing were unobtrusive to begin with and had a delightfully loose groove.

For the way it combined mercurial, on-the-fly interplay, seismic textural shifts and listening of the highest order, this gig was remarkable. In the space of two continuous sets there wasn't a longueur to be found, such was the incredible union of Black Top #5's boundary-pushing improv and fine-tuned musicianship.

Saxophonist Steve Williamson, trumpeter Byron Wallen and vocalist Cleveland Watkiss joined Black Top founders, pianist Pat Thomas and vibist/sampler Orphy Robinson, to explore the intersection of live instruments and the technology of dub, reggae and dance floor.

Britain has a grudging relationship with country music – we’ve never produced a successful country singer (although the likes of guitarist Albert Lee and several songwriters have prospered in Nashville) and our love for the likes of Johnny Cash is tempered by a contempt for much of what is marketed as country music. I’m often surprised by how  blues, soul and jazz lovers can admit ignorance of a musical form so closely related to other American genres.

You can tell by all the important upper case that the Opening and Closing Ceremonies of the London 2012 Olympic Games were the shows to be seen emoting at. Emeli Sandé can make the unique boast that she performed on both bills. That’s quite a badge of honour for a musician whose debut album Our Version of Events was released only in February, and whose songwriting career has been at least as much about supplying hits to talent-show graduates.

The moody lights and the smoke make it look like Melody Gardot is emerging from the swamp, probably somewhere near New Orleans, as she begins her set singing a capella. Her walking stick and shades (the result of a bad accident in 2003) only add to the initial feeling that she is the spiritual heir, if not the actual misbegotten daughter of a figure like Dr John, the Night Tripper. As an ex-fashion student, she oozes style, no bad thing in a jazz world that often equates scruffiness with authenticity.

Bill Withers: The Complete Sussex and Columbia Albums

Kieron Tyler

Bon Iver’s eponymous second album is nearly a year-and-a-half old now, so its bigger, richer sound – compared to the homemade sparseness of the debut – is well established. Nevertheless, it was hard not to wonder how any band assembled by Justin Vernon would function in the hangar-like Wembley Arena. Would success claim another victim?

The last time we reviewed Krystle Warren on theartsdesk one reader responded by suggesting that it couldn’t be long before this Missouri-born singer-songwriter was as big as Beyonce (although he didn’t use that exact phrase). Yet even a 2009 performance on Later with Jools Holland didn’t have the effect it sometimes has in being the first big step up for both an artist’s sales and credibility.

Sligo Live is Europe’s most westerly music festival, and its mix of indie and traditional is unique. For four nights and days, cracking traditional players fill the town’s many excellent pubs - Kennedy’s, Foley’s, the Snug, Mchugh’s and Hardagan’s - with the headliners: Wallace Bird, Lau, accordion queen Sharon Shannon, Joan Armatrading. But one name stood out on the marquee, that of Van Morrison, coming to Sligo with the promise of a very different kind of show – “Lyrics and Poetry: Emphasis on Words”, with readings of his own work and that of Yeats.