Tag Archives: harmonics

String harmonics, multiphonics and partials map {Processing}

double-bass-E1-string-harmonics-snip

There is some excellent research on performance techniques over at CelloMap.com on a variety of subjects, but the area of most interest to me lately has been string multiphonics. A criminally overlooked and beautifully fragile technique.
It seems a slightly murky area (a lot folk-lore, hearsay, speculation), but an interesting one that I hope people continue to plug away at. The two best resources I’ve found so far are Ellen Fallowfield and Thomas Resch’s aforementioned Cello Map project, and Seth Josel and Ming Tsao’s excellent new book The Techniques of Guitar Playing (2014; Bärenreiter, pp.118-24). Both map out the location of their partials in similar ways. Despite the different instruments the authors address, we are ultimately just dealing with a vibrating string and as such should not be too difficult to figure out…

double-bass-E1-string-harmonics

A recent composition of mine, yet another example of the porousness of certain borders (score .pdf, 15mb) for solo double bass uses quite a few multiphonics, and as part of the composing process I created a little Processing script which uses the Cello Map scheme. The script allows one to calculate and map out (theoretical) partials for a string of any tuning (my piece was initially going to feature some evolving scordatura but this was written out early on).

The benefit of coding this out that you can quickly generate a partial map of any tuning and as many partials as you like (though by default this is capped at 15, past then it gets tricky to find what you’re looking for). This becomes pretty helpful when searching for and identifying clustered sounding partials within multiphonics. It is worth noting however, that this is all fairly theoretical, and that real-world physics may not play as nicely on your string of choice…

You can find the script on my GitHub page. The script requires Processing, a free, open-source programming language.

My thanks to the Cello Map project for doing all the hard work on this and many other subjects.