Alloy Sounds: Non-Repeating Sound Textures With Probabilistic Cellular Automata
Contemporary musicians commonly face the challenge of finding
new, characteristic sounds that can make their compositions more
distinct. They often resort to computers and algorithms, which can
significantly aid in creative processes by generating unexpected
material in controlled probabilistic processes. In particular, algorithms that present emergent behaviors, like genetic algorithms
and cellular automata, have fostered a broad diversity of musical explorations. This article proposes an original technique for
the computer-assisted creation and manipulation of sound textures.
The technique uses Probabilistic Cellular Automata, which are yet
seldom explored in the music domain, to blend two audio tracks
into a third, different one. The proposed blending process works
by dividing the source tracks into frequency bands and then associating each of the automaton’s cell to a frequency band. Only one
source, chosen by the cell’s state, is active within each band. The
resulting track has a non-repeating textural pattern that follows the
changes in the Cellular Automata. This blending process allows
the musician to choose the original material and the blend granularity, significantly changing the resulting blends. We demonstrate
how to use the proposed blending process in sound design and its
application in experimental and popular music.