Well, you typed it. Whether you said it, I can't really ascertain.

Just spotted all this ...

'Mediation' is basically derived from Adorno, although you'll hear it used often enough in a certain kind of writing now without specific reference to him. It basically refers to Adorno's idea that art exists in a certain relation to society (base and superstructure, if you will, although Adorno wouldn't accept all the implications of those terms), but that it doesn't simply mirror society. Mediation is the process by which art's relation to what is sedimented in it (to use another term you asked about) becomes critical (another term that Ian has been known to use ) rather than naive, I suppose. [Edit: Ian's posted while I was writing the rest of my message - his explanation is possibly a bit clearer but I'll leave mine up anyway.]

One of the tensions that you might occasionally identify in the use of the term is whether mediation is an inevitable aspect of art's relation to the world, and if so, what it means to say that certain artists or certain art is insufficiently mediated. In other words, can one decide to mediate? (I'm being a little bit deliberately stupid here. Adorno would say that of course one can't decide, but that doesn't mean some art doesn't embody the contradictions better than other art.)

'Gesture': yes, I always wonder if it's worth trying to pin people who use that term down to a more precise meaning, but it basically means what it says.

'Timbre' and 'texture': I would have said (in answer to your original question) that yes, it's basically the difference between the (inherent, though variable/controllable) sound quality of one instrument and the compositional effects derived from combining instruments (or from writing in a certain way for a single instrument - e.g. 'a dense piano texture'). But I do quite like Richard's definition to do with things continuing through time ...

There are lots of terms that start off being defined quite specifically by major thinkers, and then are taken up more loosely and used in a relatively broad sense by those involved in cultural and critical theory. Examples include mediation, the other, hegemony (from Gramsci), reification (from Lukács), deconstruction (from Derrida) and recently any number of terms from Deleuze which look flashy and frequently serve to make things much more impenetrable than necessary (deterritorialisation, molecular/molar, majoritarian/minoritarian, desiring-production, etc., etc.). The popularisation of such things is a mixed blessing; often when, say, the word 'deconstruction' is used, something as simple as 'taking apart' or 'unpacking' would do fine; Derrida's original conception is stripped of that which makes it unique. But in the case of mediation, reification, and a few other terms (not necessarily 'the other') there does not seem to be any simpler term which is appropriate. Overall, I feel some of the concepts and vocabulary bequeathed by the German idealist tradition has wider application and significance than the more tricksy and dazzling stuff that comes from French post-structuralism and the like. When one has read countless articles that brandish their Deleuzian jargon on their sleeves at every possible opportunity, and then after finally penetrating that the dearth of any real arguments is revealed....

<gasp of surprise>

I couldn't work out where that 'oriental' came from either, George, but I didn't read the whole thing so I thought I might have missed something. It did seem an unlikely intrusion though. I blame Sorabji.

I think Adorno's survived enough attacks now that he won't be killed off by Brian O'Connor, though I'm not sure whether O'Connor was sure whether he was really aiming to produce a 'damaging critique' anyway ... Interesting stuff though, as you say.

My own beef about Adorno was always that he came up predictably often as the only modern thinker a lot of musicologists seemed to be aware of (e.g. http://www.lancs.ac.uk/sma/news/2002_07_winter.htm , if you really want an embarrassing view of my younger self), though I haven't been heavily involved in institutional musicology since about 2003 and Ian has given me to understand that Deleuze is much more visible these days than he ever was back then.

Indeed, Tim, except that 'outside musicology' Adorno seems to me (I'm going to face the slings and arrows of Pace and quartertone for this!) to be somewhat out of fashion in a way that certainly isn't the case for Deleuze.

In fact, Adorno's been out of fashion for so long in philosophy departments that by now he's back in fashion, and I think Adorno scholarship has probably benefitted from the break in a way that what one might term 'Adorno musicology' hasn't ...

On the other hand, there are some intelligent Adorno musicologists and, I expect, some less intelligent Adorno scholars in philosophy departments, so I guess all that's really required is a bit of intelligence and imagination.

Were any of them from a philosophy department, just out of interest?