a few months ago I was appreciative here of the Philip Brophy anti-ephiphany in the back of the Wire in which he aired some heterodox opinions about Johnny Cage, and I noted also that Stockhausen, despite at one point being influenced by the man's theories, later said Cage had zero musical instincts. Then the other week, perusing Andy Mackay's useful and attractively illustrated 1981 book Electronic Music, I was amused to see a lengthy explication of Cage's ideas/techniques/influence immediately followed by this caveat:

“It is a problem for the listener with many of Cage’s works that they are often unpleasant to listen to and extremely boring. Cage is well aware of this, taking the moralistic line that such an ordeal was good for the perceptions generally.”

Now I come across, in Paul Griffith's succinct and insightful 1979 A Guide to Electronic Music, this bit on Cartridge Music:

"The result is a miscellany of bizarre and very often unpleasant noises... The aural experience of Cartridge Music is bound to be something of a trial..."
and on the whole indeterminacy/open compositions thing:

"It is open to performers to make a 'beautiful' realisation, but the most authentic recordings, such as Tudor's of Variations II, oblige the listener patiently to accept the boring and hideous as well".

So it's official! John Cage: great, but unlistenable; Important, but shit.