“It’s not often you get a global superstar down at the Elephant and Castle,” marvelled a local who spent the evening dancing like a dervish to the infectious music of Manu Chao, who had breezed into London for a rare show last night off the back of a short tour of Japan and the West Coast of America. The first person I saw as an usher was Colombian philosopher Oscar Guardiola-Rivera whose book What if Latin America Ruled the World? suggests - among many other things - that the US is becoming the next Latin American country. Like the others he was wearing a Colombiage T-shirt - the organisation for which this was a benefit.

Paradoxically, the greater the number of established artists you find yourself comparing a new talent to, the more original you are eventually forced to conclude this new talent is. So let’s get those comparisons out of the way: this Kansas City gal sounds a bit like Cassandra Wilson, Joan Armatrading, Me’Shell NdegéOcello, Joni Mitchell, Nina Simone, Sly Stone, Bob Dylan, Bill Withers… and the list could go on. But more importantly Krystle Warren already seems to exude the same kind of gravitas as all of this illustrious roll call.

First up, a confession. I’m one of those who’ve never considered KT Tunstall to be quite the real deal. She’s sometimes described as indie, but I’ve always found her more background music for filling out a tax form to than someone to help you through a lost weekend. On a recent single she sings about being “still a weirdo”, but it comes over to me about as convincingly as Guy Ritchie’s accent. Weirdo? That cutesy Sino-Scottish face and Jimmy Krankie accent are only a curio when stacked up against mainstream AOR, which is clearly what she doesn’t want to be. To me she’s indie-lite. Or Melua-heavy. Am I alone? Last night I sure was.

There was a rumour floating around the packed Forum last night that David Cameron was in the audience. I did not spot him on my way in, but he did choose The Killers' “All These Things That I've Done” as a desert island disc in 2006 and I imagine that, being a man of firm convictions, Brandon Flowers still floats his prime-ministerial boat. Clean living, passionate, nothing too controversial – just like the PM before he pulled the knife out and started plotting to slash away at the country's finances.

"The Legend of Axl Rose" sounds like the title for a long and fanciful western movie, about a bandit who defies the law and even time itself. In person, wayward vocalist Rose does indeed resemble some kind of picaresque outlaw who rules his own eccentric kingdom, and he lent much-needed gaiety to this sprawling performance by constantly ringing the changes on a huge wardrobe of hats, jackets and multi-coloured T-shirts.

Twenty-five years ago, a-ha achieved something unprecedented for a Norwegian band: they entered the British charts. The week of 5 October, 1985 saw “Take On Me” enter the Top 40. Three weeks later it peaked at number two. To mark the anniversary, a-ha have chosen to do two things: embark on a worldwide farewell tour and play a special show at the Royal Albert Hall, running through their debut album, Hunting High and Low, with a full orchestra. That not being enough for a full show, they also played its follow-up, Scoundrel Days.

The great music writer Nick Tosches put me onto James Luther Dickinson. In Where Dead Voices Gather, his self-indulgent but fascinating book about the obscure early-20th-century minstrel performer Emmett Miller, Tosches kept touching on Dickinson, a Memphis musician and occasional Rolling Stones sidesman (he played piano on "Wild Horses").

I would call them burglars: musicians from the experimental rock, electronica and sound-art traditions who cross the genre divide, sneak into the world of classical music, pillage its more easily pillaged valuables, thieve its respectability, filch its original ideas, and sprint back breathlessly to their wide-eyed fans to show off this brilliantly clever "new" classical music (much of which is made up of techniques that George Benjamin would have grown out of by the age of six) in double quick time lest someone from classical music pins them down for long enough to inform them how rubbish

Happy Birthday, Tony! Last night the great Nigerian musician celebrated the fact that he has spent 70 years on the planet, with 52 of those years exploring – as no other drummer has explored – the humble kit drum (or drum kit if you prefer). This standard arrangement of bass drum, snare drum, toms, cymbals and percussion has been the engine behind most popular music for only a couple of decades longer than Tony himself has been bashing away at the things for.