Why change tonal centers?

Modulating to different tonal centers seems like something predominantly Western. I've read of thoughtful classical Indian composers being appalled by changing tonal centers at concerts, and getting up and leaving. I don't understand exactly what such people have against changing tonal centers, but then again I don't understand why we do it in the first place.

Changing modes, while keeping the same tonal center, I can understand more. It offers a change in the harmony of the music; a new flavor. But when it comes to changing from C ionian to G ionian, for example, what is the use or novelty besides the modulation itself? I know the assumption that it is supposed to create excitement or tension, even if the listener is not aware of it, but what is there to objectively support that notion? The only real use I can see, is to shift the range so that different timbres can be used for certain intervals, but how often do composers actually modulate for that reason?

Any insight? I would be appreciative to learn of something I'm missing here.

I like the idea of changing tonal centres because it gives a composer greature area to expand on his idea.

In indian ragas, which, to be perfectly honest, tend to be very repetitive, maybe it's just their worldview.

There are a lot of reasons to change tones but I just say this one since rarely anyone does.

Let's say you have a lead with a violin and you know to give that part to a trumpet. Well, if you give the exact notes the trumpet(tranposing included) it wouldn't really produce the same effect because the range is different. IT would be better just to change the key(with a seconadry domiant) into the more middle range of the trumpet.

Yeah, that was the one way I could see modulation being useful. Otherwise, it seems like something that isn't really necessary but we sometimes feel obligated to do nonetheless, you know what I mean? Long-term modulations anyway. I still think the effect of changing key has a really nice immediate effect.

I think the idea of a tonal center is just an analogy that we place upon the music.

When that analogy is applied heavily to musical form, you'll get all the subtle things that Classical composers do to put off returning to the center. This is a nice idea, I suppose, but I don't think it has all that much to do with musicality.

If a piece starts in one key and ends in another I'd be damned if I knew that was the case (entirely by ear).

I have a tendancy to serialize my tonal centers... In a strange way I'm actually doing this inorder to get to "the monochord" which is like what you would do with dronal music.. justintonation and all that.. La Monte Young.. etc.. Which is actually rather close to what's up with the Indian music in the first place.. For me the rational of all this madness and mayham has something to do with my take on serial music.. Which has something to do with "Aesthetic experiance as cognative event." Beauty having something to do with pattern recognition.. but also the idea that what we notice is "how something is different from the norm" which, perhaps, could be defined statistically.. So by shifting my key centers... I'm sort of like point the following:.. we often hear the difference / relationship between stuff.. rather then the thing in it's self.. This gets us pretty close to issues of Kantian metaphsysics.. as well as what John Cage was after we he would talk about being interested in "auditioning sounds." So I'm seeking some place somewhere between music and sound.. a place of figure ground ambiguity..

The other reason I sorta serialize my tonal centers is cause I just don't know any better.