[Haskell-cafe] Analysing music

[Achim Schneider]

Henning Thielemann <lemming at henning-thielemann.de> wrote:

> 
> On Thu, 5 Jun 2008, Achim Schneider wrote:
> 
> > The recent discussion about Markoff chains inspired me to try to
> > train one with all the Bach midi's I have on my disk, collecting
> > statistics on what intervals tend to get played simultaneously,
> > which follow others and in which way the pitch offsets from its
> > mean, so that melodies fall and raise "naturally".
> 
> I don't know, if you already found that one:
>   http://darcs.haskell.org/haskore/src/Haskore/Example/Kantate147.hs
> 
> Surprisingly I also tried Markov Chain on a Bach song. But my
> approach was too simplistic in order to produce a nice new song.
>
Yes, you need to take both dimension of music into account, that is
time and polyphony. Bach uses quite exceptional polyphony from time to
time, but it always stays harmonious: You have to have eg. a 0%
probability of ever playing a note and its minor second. The
probability of a note and its quint will most likely be at least 50%,
but then there are chords that sound atrocious if it's there. 

What I need is basically one view of the data as list of used chords,
and one graph of all possible time-linear progressions... that is,
voices, for a definition of "voice" that makes the guitarist in me
shudder.

Seems like I'm going to make close acquaintance with fgl, after all.

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