Chroma Palette : Chromatic Maps of Sound As Granular Synthesis Interface

Donaldson, Justin and Knopke, Ian and Raphael, Chris

Proceedings of the International Conference on New Interfaces for Musical Expression

Chroma based representations of acoustic phenomenon are representations of sound as pitched acoustic energy. A framewise chroma distribution over an entire musical piece is a useful and straightforward representation of its musical pitch over time. This paper examines a method of condensing the block-wise chroma information of a musical piece into a two dimensional embedding. Such an embedding is a representation or map of the different pitched energies in a song, and how these energies relate to each other in the context of the song. The paper presents an interactive version of this representation as an exploratory analytical tool or instrument for granular synthesis. Pointing and clicking on the interactive map recreates the acoustical energy present in the chroma blocks at that location, providing an effective way of both exploring the relationships between sounds in the original piece, and recreating a synthesized approximation of these sounds in an instrumental fashion.