[Smt-talk] accellerandi-pieces

[Thomas Noll]

Dear colleages,
with students in theory class we have been working on the idea of an  
infinite accellerando (or ritardando) in analogy to the illusion of  
infinite ascend (or descend) in pitch height in the Shepard scale (or  
glissando). The solution we came up with is a combination of
(1) a non-periodic self-similar rhythm (such as investigated by Norman  
Carey and David Clampitt in their 1996 PNM article: "Self-similar  
pitch structures, their duals, and rhythmic analogues"), which is  
played simultaneously at several speeds, where "old" levels fade out  
and new levels fade in through a Gaussian envelope for the amplitude,  
and
(2) an exponential time flow (which is the physical time of  
performance as a function of symbolic score time). All of the  
(infinitely many) voices silently start simultaenously at minus  
infinity  ;-)
One of the students, Christobal Massis Valencia (percussionist),  
realized a ritardando (in combination with an "infinite" descend) as a  
homework on that class:
http://user.cs.tu-berlin.de/~noll/sqrt2
Thomas Noll


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Thomas Noll
http://flp.cs.tu-berlin.de/~noll
noll at cs.tu-berlin.de
Escola Superior de Musica de Catalunya, Barcelona
Departament de Teoria i Composició

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