In 1960 John Cage performed his piece Water Walk live on the game show I’ve Got a Secret (thanks to Jenny Diski for pointing it out). Back then it must have seemed like an elaborate joke at Cage’s expense. The presenter who introduces him is fatuous and sceptical, rolling his eyes when Cage tells him he is going to knock radios onto the floor (a union dispute over who should plug them in meant he couldn’t switch them on – a chance intervention he was no doubt delighted with). ‘I’m with you boy,’ the presenter says patronisingly.