[sdiy] Generating acyclic waveforms?

[Ingo Debus]

Am 21.03.2010 um 23:09 schrieb cheater cheater:

> Also according to Wikipedia the Gamelan has a very stretched  
> harmonic series.

Do you mean the harmonic structure of the sound of single instrument  
used in a Gamelan, or do you mean the scales used in Gamelan music?

If the former, well "the Gamelan" is not an instrument, it consists  
of quite a lot of very different instruments. It's impossible to make  
a general statement here.

If the latter: there are two scales used in Gamelan music, called  
Slendro and Pelog. If you look at a Gamelan, most instruments are  
there twice: one Slendro version and one Pelog version.
The interesting thing here is: both scales have intervals close to a  
pure fifth (i.e.frequency ratio 3:2), and the Slendro "fifth" is  
sharp compared to a pure fifth, while the Pelog fifth is flat.
Our western fifth (12 tone equal tempered) is quite spot on, I think  
it's only about 2 cents off a pure fifth.


> I think it might be the same situation that causes gongs and other
> such stuff to have such a very inharmonic sound, but I'm very far out
> of my expertise here.

Ever heard a Gamelan Gong? Unlike the gongs we know it has a very  
distinct pitch.

Ingo