One note played forever would still vary over time.  Sound itself is dynamic and kinetic, in principle.  The effect can be constant.

I'm pretty happy, with terms like 'art' and 'music' to allow people their own personal definitions; for me it's something that relates in some way to the established musical tradition.

Amen to that, ros. 

La Monte Young's Composition 1960 #10 Draw a straight line and follow it has been realised as one very long note.

Cage's book Silence contains possible pointers, especially the articles entitled The future of music: credo and Experimental music.

My copy fell open at this paragraph (from the latter article):

"And what is the purpose of writing music? One is, of course, not dealing with purposes but dealing with sounds. Or the answer must take the form of paradox: a purposeful purposeless or a purposeless play. This play, however, is an affirmation of life - not an attempt to bring order out of chaos nor to suggest improvements in creation, but simply waking up to the very life we're living, which is so excellent once one get's one's mind and desires out of its way and lets it act of its own accord."

Which is not a definition, but just a paragraph which I thought may be of interest . . .

Intent on whose part, George ?

I'm not. (There you go: it takes all sorts ...)

Perhaps I could be convinced to accept 'organised or giving the impression of being organised' - after all, 'organised' begs the question 'How do we know?'

Here's a poem by Seamus Heaney, which just popped into my head unbidden (I hope I've remembered it more or less accurately). It's called 'Song', funnily enough:

A rowan like a lipsticked girl.
Between the main road and the by-road
Alder trees at a wet and dripping distance
Stand off among the rushes.

There are the mud-flowers of dialect
And the immortelles of perfect pitch,
And that moment when the bird sings very close
To the music of what happens.

Now, that's a metaphorical usage of the word 'music', obviously. But I'm not sure we'd accept it at all if it didn't bear some relation to our ordinary sense of the word.

Re intention, I would have thought the intention of the listener is at least as important as that of the composer (which, like 'organisation', is not something we ever know for certain).


Added: Oh, I see autoh and martle got there before me on intention.

I've indeed long been of the view that the required organisation can in some cases even be exclusively on the receiving end of things. As in the old Cage story where a listener says what a wonderful structure such and such a piece has to which he replies 'well, I didn't put it there'...

And of course:

"For where two or three are gathered together in my name, there am I in the midst of them."

As I said a couple of days back, I reckon if it's good enough for God it's good enough for music.

Well, again FWIW, I agree. That is a metaphorical use of the word, like the music of the sea, or the music of a tap dripping. It is 'as if' music. 'As if' intentional. (Or if we happen to think that Neptune or the Tap God are behind it, then actually intentional, but we have generally come to think of them as metaphors too).

I think that is a more useful way of looking at it than a definition which includes all and any sounds as 'music'. The latter is too general to serve its purpose. (And I think good old 4' 33" counts as music on my definition. Ask Mike Batt  . But don't we lose points for mentioning 4' 33" or am I getting it muddled up with Hitler?)

But, also FWIW, I don't think it actually matters very much how 'music' is defined. Nothing of any great moment turns on it. It isn't as if it is a concept at the centre of any fundamental theory which needs to be precise. It's a bit like worrying about using the word 'hedge' before you have pinned down exactly where hedges stop and 'two or three bushes gathered together' start.