Re: Rhythm perception

[Dan Ellis <dpwe@xxxxxxxxxxxxxxx>]

>>  We were discussing rhythm patterns the other day and the question came
>>  up about how one determined the start of a pattern.  

I think this is the "downbeat detection" problem, which is distinct from
the problem of deciding the main repetitive period of the rhythm
i.e. the spacing between downbeats.  I'm not a musicologist, but I've
tried to build a system to align downbeats in different rhythm patterns,
so I've thought about it a little.

Here's one piece of evidence: Tristan Jehan presented a poster at the
recent Mohonk WASPAA on a machine learning approach for predicting 
the downbeats, which he tested on a style of Brazilian music called 
maracatu.  He played the maracatu examples to listeners familiar with
northern-hemisphere western music, and they could not identify the
downbeat - but of course maracatu fans have no problem indicating the
appropriate downbeat.

  http://web.media.mit.edu/~tristan/Papers/WASPAA05_Tristan.pdf

That to me is powerful evidence that downbeat is a cultural norm and not
strongly based on some universal.  

  DAn.