Re: Rhythm perception

[Michael Fulton <michaeljfulton@xxxxxxxxxxx>]

> We were discussing rhythm patterns the other day and the question came
> up about how one determined the start of a pattern.  If there is a
> heavy emphasis on one beat of the sequence then I can understand that
> that is taken as the first beat.
>   But if the sequence is unemphasised how does one decide?  Or do
> people decide differently, or is it cultural?
>
> I am not sure where to start to look -- as ever this is outside my
> general field of study -- but I though this list might be the place
> to ask for clues.
>
> I hope I have explained the question sufficiently!
>
> ==John ffitch

As far as I am aware the two most successful systems to date for extracting 
information about musical measures are by Klapuri and Goto (Klapuri being 
the better). These both identify the foot tapping rate or tactus as its 
called and also the start of each measure. The system by Goto relied on 
detecting chord changes and Klapuris system looked for rythmic 
fluctatuations in the signals amplitude i.e. low,loud,-,loud.
However, both these relied on their being some form of emphasis/change and 
were designed for primarily western popular music. If the sequence is 
unemphasisied then I suppose it really is a purely  subjective decision 
based on experience and culture.

The papers I have mentioned are

http://www.cs.tut.fi/sgn/arg/klap/sapmeter.pdf

and

http://staff.aist.go.jp/m.goto/PROJ/bts.html                   No.9 on page

Hope this helps as this is also a problem that has been troubling me 
recently i.e. given a peice of music how do we reliably regocnise the start 
of each measure ?

Mick