Romance

Lately I've been reading "Music and the Ineffable" by Vladimir Jankelevitch. I came into contact with this book after a particularly interesting class I attended at the V.C.A.M.
In it, Jankelevitch states that (instrumental) music does not express anything in and of itself, rather, it is the listener and performer who project meaning onto a work.
Vocal music is discussed slightly differently, obviously due to it's link with poetry and a language that, for us, has a much more direct and unambiguous meaning.
While I don't profess to be an expert on every aspect of the philosophy in this book, a few things have really leapt out at me that I feel express ideas I had but never knew how to put into words. Namely, the idea that music may be like many things to many people, but can never be the same thing to everyone. This is, in fact, one of the characteristics that makes it so enjoyable and so unique. Therefore it's futile to compose or perform music with the idea that you are somehow communicating the same, deep message to all of human-kind. This stance flies in the face of many of the Romantic era composers, where one of the prevailing philosophies, as I understand it, was that music connected with the human 'soul' on such a deep level that it transcended cultural, generational and socio-economic divides and therefore expressed the most universal, and deeply 'human' aspects of all human-kind.
Therefore music expresses nothing, as well as everything: it becomes nothing to everyone, but something deeply personal to anyone who cares the become involved in it.
Also, Jankelevitch cites improvisation as a prime example of the 'circular causality' that pervades musical forces, that is, that in music, nothing can exist without effecting and being effected by, other things. Therefore, idea an action cannot occur following on from one another. True music is made with both of these events occurring simultaneously. "One deliberates by choosing or one thinks by saying."
There are many more passages I have read so far that struck a particularly strong (all-note, -all interval) chord with me, but one of the things this has really got me wondering is why so much jazz is so romantic in approach. It seems that it has been part of the jazz tradition (possibly) since it's inception. This may have something to do with jazz's beginnings being so close to the 19th century in terms of years.
While teaching an undergraduate student today, and demonstrating the phrasing of the like of Bud Powell and Bill Evans and their use of accent and dynamics, I was met with something along the lines of "it's so full of emotion". What is it about these musical techniques (dynamics and phrasing) that induces such an immediate and self-assured response? At the time I responded with something similar to the third sentence in this blog post, and then hypothesised it could have something to do with the fact that the opposite never occurs in nature, that we are most often surrounded by sounds that are in a constant state of flux. Now I'm not so sure if this is a valid argument, even though it may be true.
I must confess, I'm only halfway through the book, but I'm enjoying thinking about it quite a bit.