Vincent D'Indy and the breath of music

I'm going to have a musical interlude - partly because I think it relates to other things I've been talking about recently.

Of all the music theorists I admire, I find the most interesting (and the  most useful from a compositional point of view) is the French composer Vincent D'Indy. D'Indy is an unusual character - a devout Catholic who tended to be musically conservative, opposing the 'parallelism' of Debussy, favouring (like Schoenberg) an idea of harmony as functional. But most importantly, he founded his own school with his own pedagogical approach.

Music for D'Indy was a spiritual matter. In his "Cours de composition musicale" (which I quote here, and you can download here: http://imslp.org/wiki/Cours_de_Composition_Musicale_(Indy,_Vincent_d')) D'Indy states that it's fundamental elements are melody, rhythm and harmony. He has many fascinating things to say about the first two, but it's harmony I want to focus on here, because it was D'Indy's harmonic theory which was highly influential with a number of great composers who came after him - most particularly Olivier Messaien and Michael Tippett.

D'Indean theory of harmony is the most striking thing. He draws our attention to the cycle of 5ths, suggesting that in the major mode, a move up the cycle of 5ths is a process of increasing 'light' (montée vers la lumière), whereas descending increases darkness (la chute vers les ténèbres). This leads him to produce the following table:

Thus D'Indy sets out his harmonic system. The 'lightening' and 'darkening' processes are reversed when the mode is minor. In the minor mode, descent down the cycle of 5ths is lightening, and rising is darkening. 

What really grabs me, though, is what he says next. That a rise up the 5ths in the major mode requires the expense of effort, whilst falling down the 5ths is a 'detènte', a 'letting go'. 

It is like the muscular movement of the stomach.

What fascinates me about all this is that it presents itself as an approach to harmony which is part-biological and realistic in a bio-pschosocial respect as well as the more common physical realism. This is in contrast to both to Schoenberg's approach to functional harmony (who may be 'idealistic'), or to Schenker (who may be ultimately considered naively realistic in pinning too much to the harmonic series).

The idea of biological tension and release tie into so much else of what is interesting me at the moment. But most of all I am thinking about the simple application of cybernetic ideas to music analysis which I did last year some time. I had an interesting comment about my commentary of Lachenmann (see http://www.youtube.com/watch?v=rdVpOyN5Y-U) Might D'Indy help with a re-interpretation of prolongation?

Thinking about this, the central issue about prolongation is that in Schenker it is restricted to tonal music - the perfect cadence is central to his prolonging architecture. But what is the I - V - I progression if not a rising of effort and then a release? But the rising of effort doesn't have to specifically take that form. Indeed, in polytonal and atonal music, where there is simultaneous rising and falling, simultaneous keys, etc, moments where falling or rising fade in and out. As they do so, I think there might be a way of constructing a mechanism for describing prologations which are not as restrictive as Schenker's.

But I'm more interested in this because I wonder whether life itself is prolongation - or more formally, that the form of life is a way of prolonging life. That may be another way of saying 'viability', but it is at least a way that infers that we breath in and we breath out; we expend effort, and then we release it.