[LAU] Progressive Quantisation

Fons Adriaensen fons at kokkinizita.net
Sat Sep 15 12:27:51 EDT 2007

On Sun, Sep 02, 2007 at 09:07:52PM +0100, Folderol wrote:

> However, I don't see how to resolve the problem of a rouge note that
> should actually be totally ignored for the purpose calculating the
> trend if it falls far enough outside the predicted curve. Not only
> could this give false timing on the reference track, but as this track
> is then used to pull all the others into line, it could give some very
> strange effects if (say) a bass track is used and some notes are
> deliberately played slightly off time.

If the loop is just the track the overall tempo (rather than responding
immediately to sudden tempo changes - a different and more difficult
problem) then its bandwidth can be small, and an occasional off-beat
note will not disturb it very much.

But the best solution would be to build some 'intelligence' into the
detector, making it actively decide to ignore certain events that 
don't fit the expected pattern. If the processing is on a file rather
than in real time you can also include techniques such as backtracking
- reviewing an earlier decision, and awareness of higher level structure
and musical expression. This is also the solution to the more difficult
problem of tracking sudden tempo changes as occur for example in the
interpretation classical music. 


Follie! Follie! Delirio vano è questo !

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