It was curiously gratifying to learn, last week, that Darmstadt – that sanctum sanctorum of new musical experiment – was quite often emblematised by an image of the Hochzeitsturm, a Jugendstil tower in the town with a profile that looks as if it's an architectural rendering of the gesture the Americans call “flipping the bird” – a single-digit salute that invites its recipient to depart without further conversation. This fitted a personal prejudice. Like quite a lot of people I've never really known what to make of serial music, or how you might go about enjoying it in anything but a punitively cerebral way. That is, I can understand people submitting to it as an intellectual exercise and even relishing the challenge it presents to inherited musical tradition. But I have some difficulty in imagining anyone putting on a recording of Luigi Nono or Karlheinz Stockhausen, say, for reasons of pure pleasure. What's more I couldn't help but feel that my alienation, as an ordinary listener, was always part of the point as far as its practitioners were concerned. There was a Millwall-supporters quality to the tight sodality of hard-line serialists – “everybody hates us, we don't care” – which seemed to be perfectly summed up by that five-fingered tower.

I saw the poster that stirred this thought in The Sound and The Fury, BBC Four's useful (for outsiders, at least) introduction to the history of 20th-century music. And coincidentally I'd just come from an exhibition that celebrated another fraternity (they were almost exclusively men) of radical experimenters – the Barbican's exhibition Dancing Around the Bride, which details the impact on four very significant American artists of the work of Marcel Duchamp. In both cases old forms were being abandoned and old verities about art being overthrown. In both cases the definitions of what might count as "art" or "music" were being expanded to the point that more conservative audiences were distressed and even angry. But the outcomes from these two cultural developments were very different. They can, crudely, be summed up by box office.

Tate Modern, the inheritor of a Duchamp-ian tradition of conceptual art, is now one of the capital's biggest attractions. Contemporary classical music, by contrast, remains something of a difficult sell. Audiences for the former can be counted in millions. For the latter in thousands.

I'm not making claims about the respective merits of the art, only noting that a large audience was able to accommodate itself to new concepts in visual art in a way that never really happened with the musical avant-garde. And I found myself wondering why that should be as I went round the Barbican. My best guess would be that visual art was less fearful of pleasure. Its declaration of independence from the past was to abandon representation – an unmissable badge of difference which wasn't as easily accessible to composers. Music was obliged to break with melody instead, and so severed a cord that might possibly have towed an unsettled and uncertain audience behind it.

What was striking about The Sound and the Fury's account of Darmstadt was the doctrinal severity of the movement. What was striking about Dancing Around the Bride was the sense of restraints being thrown off – and a kind of tripping delight at the very different forms pleasure could now take.

And there can't be much doubt that the end result in each case was very different. Where Darmstadt gave the audience the finger, Duchamp – and his admirers – beckoned them in.

Chorus Line quote's out of step

Before this week, I didn't know that the dedication to A Chorus Line, triumphantly revived this week, is "to anyone who has ever danced in a chorus or marched in step... anywhere". It seems recklessly over-generous to me. Anywhere? Really? Even Nuremberg, where the storm-troopers high-kicked their way to a sense of Aryan supremacy? Or North Korea? I think I know what Michael Bennett was getting at – that melting away of identity that accompanies all kinds of human synchronisation, from line-dancing to army drill – but I still feel he could have been a little more picky about who he welcomed into the hoofers' club.

Nothing to fear but fear itself

Troubling to see that People Like Us – BBC3's documentary about Harpurhey in Manchester – has been accused of leaning on the scales in its account of the community. Some locals are apparently furious at the way they've been depicted and the local MP has taken up their cause. But some of the complaints were a little baffling. One of those protesting was Lisa Walker, whose son Dale featured. She's reportedly indignant that his apprenticeship wasn't mentioned and seems to feel he was presented as a wastrel. But I thought that Dale was charming – full of an enterprise limited only by lack of opportunity. Which made me wonder if some of the protestors are furious about the reactions they fear they'll get, rather than those they have.