[PD] Waveform Analysis?

[Mathieu Bouchard]

On Thu, 15 Apr 2004, Ian Smith-Heisters wrote:

> I'm not familiar with Markov-chain modeling, but it might be an
> interesting endeavor to try to describe genres of music using first
> order logic ;).

First-order logic is nice, but I wouldn't try to make hard
classifications, so I wouldn't use truth values as distinctions between
styles, but rather create continuous metrics, possibly involving
vectorspaces. Of course this can be fitted inside a first-order predicate
logic context, as almost everything can... but pure logic of black/white
binary oppositions seem limitative to me, so in my system truth-values
wouldn't play a very central role.

> A lot of people say that music is a mathemetical language so a more
> mathematical approach may tend to be more efficient.

More mathematical than what? Markov chains/tables are mathematical, but
you seem to realise that too, so I'm not sure what you mean by more
mathematical...

> Once you've defined your language of notes, measures, tempos etc (a
> much smaller vocabulary than traditional natural language)

That is debatable. In NLP and programming-language parsing, it can be
considered that there is a language in which the vocabulary is just
letters and characters, and that this language is used to construct a
higher-level language in which the vocabulary is made of words, and so on.

This modularisation/factorisation of a language is very much useful, and
it can be seen in how compilers are usually constructed. Using Chomsky's
taxonomy, a programming language is usually a contextful (type 0 or 1)
language, but it is factored in a contextfree part, handled by lex/yacc
parser-generators or similar, and a contextful part, parsed more
explicitly. The context-free part (type 2) is in turn factored into a
regular part (type 3) handled by Lex and a irregular part handled by Yacc.

How this is relevant here is that, in a factored language definition, at
the level 3 the vocabulary is letters, at the level 2 the vocabulary is
tokens (usually words), and at the level 1 the vocabulary is
phrases/sentences/statements/... And that a musical language can be
factored in the same way, or in any way felt to be appropriate. Notes may
be at the base level, and scales may be higher-level, and themes may be
higher-level even, and so on.

> you could let the modeling search go at it. Or something. I only have
> a cursory understanding of AI,

so do I...

> I'm just musing at this point.

so do I again =)

> It takes a signal input and outputs the song's genre and aesthetic
> quality on a scale of 1-10.

Actually, even though I think many æsthetical judgements can be
formalized, not all can, and even, who gets to decide the æsthetical
rules? They tend to be very contextual and ever-changing; well, unless the
Academy or the Church emits strict rules, but we're not in that era
anymore =) There is a multitude of possible æsthetical models and in the
end it all depends on which crowd you are trying to please -- even within
_one_ so-called genre...!

________________________________________________________________
Mathieu Bouchard                       http://artengine.ca/matju