We all know people who listen to their music from iTunes, aren’t fussed with CDs and use their computer as the sole source for their listening. They’re listening to MP3s, the file format developed for portable players. But MP3s are compressed files with less data than those on a CD. Why listen to this fast-food version of music at home? Do so and it’s a nail in the coffin of sound quality.

Benda Bilili! is in some ways very Hollywood – the story of a dream of stardom which comes true despite incredible odds. On the other hand, the subject matter of a group of homeless paraplegic musicians in a band called Staff Benda Bilili (which means something like “looking beyond appearances”) in one of the most dangerous cities in the world – Kinshasa – is hardly Tinsel Town. As the film-makers relate below, they themselves were also “nobodies” when they started filming, in the sense that they had no experience of film-making and little money.

Misery may be folk music’s stock-in-trade but no one does it quite like the British. Maybe it’s part of our heritage. We are a nation, after all, that has not only invented a drink called bitter but have a brand called Doom Bar. And within the UK, there’s one particular volume of folk music that is unparalleled in its bleakness. It’s called the Northumbrian Minstrelsy, and it’s the first place Rachel Unthank, of critically acclaimed folk group The Unthanks, goes to look for new songs to cover.

Oslo’s annual by:Larm festival celebrates Nordic music. Over the three days, just under 180 acts play Norway's capital: 142 are Norwegian, 15 are Swedish, with single figures each for Iceland, Denmark, Finland and even Greenland. Time presses, and hard choices have to be made about what to see. This year, by:Larm also hosted the inaugural Nordic Music Prize, awarded to Iceland’s Jõnsi, for his recent album Go. Overjoyed, but overwhelmed, in reaction he said little more than, “Thank you so much, I’m really bad at this.”

There's been a lot of waffle lately about rock'n'roll being dead. This is down to mainstream radio turning its back on guitar music in favour of a stew of electro-pop and R&B, and the fact that just three spots in the Top 100 UK bestselling singles (ie downloads) of 2010 were held by rock songs (for the record, Journey's "Don't Stop Believing", Train's "Hey, Soul Sister" and "Dog Days are Over" by Florence + the Machine).

I didn't realise how much I liked dirt. Especially New York dirt. I was going to do a rant about boutique designer hotels, which seem ubiquitous in Manhattan. Major case in point: the Gramercy Park Hotel, where I used to stay in the Nineties and Noughties. It was independent, a bit scruffy, with a great bar full of artists and rock'n'roll types and other degenerates, a perfect location and cost about a hundred dollars a night. Last time I looked it had been ponced up – fish tank in the reception, a Buddha, fancy doorknobs and good-looking but no doubt useless staff. Clean as a whistle.

I am far from the first - and in very good company - to worry about the over-commercialisation of flamenco. As far back as in 1922 Manuel de Falla and Federico Garcia Lorca, respectively Spain’s greatest composer and poet of the time, decided to organise a singing competition in Granada in which only singers from the villages were allowed to enter. The polished, preening urban stars of the Café Cantantes were ineligible. My resistance to the genre was partly to do with the Gypsy Kings, amusing enough when you first heard them, but irritating beyond words when heard for years in every wine bar in the world.

The idea of "selling out" has clung to popular music, and indeed most art forms, for a long, long time. In our postmodern techno-consumerist society it's an increasingly outdated and irrelevant concept. The book Faking It: The Quest for Authenticity in Popular Music by Hugh Barker and Yuval Taylor shrewdly takes the whole notion of selling out to pieces, from the blues of the early 20th century to Moby's deconstruction of those blues decades later. Or rather, it simply points out there was never such a thing as a core purity from which anyone could sell out in the first place. Really, Barker and Yuval say, there's no such thing as authenticity and therefore no such thing as selling out.

If you’ve never heard a Gang of Four track, you probably still know their music. Their influence is all over the Red Hot Chili Peppers, Bloc Party, Franz Ferdinand, and R.E.M to name but a few of their fans. And that's just the musical legacy. Because Gang of Four, primarily active from 1978 to 1983, if they changed anything, changed the way bands considered the role of rock music. Paul McCartney may have wanted to fill the world with silly love songs, but Andy Gill and Jon King wanted to jam the airwaves with social injustice, war and disconnected lives.