Chroma Toolbox: Matlab Implementations for Extracting Variants of Chroma-Based Audio Features

Chroma-based audio features, which closely correlate to the aspect of harmony, are a well-established tool in processing and analyzing music data. There are many ways of computing and enhancing chroma features, which results in a large number of chroma variants with different properties. In this paper, we present a chroma toolbox [13], which contains MATLAB implementations for extracting various types of recently proposed pitch-based and chroma-based audio features. Providing the MATLAB implementations on a welldocumented website under a GNU-GPL license, our aim is to foster research in music information retrieval. As another goal, we want to raise awareness that there is no single chroma variant that works best in all applications. To this end, we discuss two example applications showing that the final music analysis result may crucially depend on the initial feature design step.