Audio tonality mode classification without tonic annotations

Traditional tonality mode (major or minor) classification or audio key finding algorithms often rely on tonic annotations (key names) of the training songs. However, unlike classical music whose keys are usually explicitly labeled in their titles, the keys of numerous popular music are hard to obtain. In contrast, it is much easier to only label the mode for each song. With only modes labeled, traditional approaches to key or mode classification cannot be directly applied, due to the lack of the reference point to transpose and align the chroma features with different keys. In this paper, we present an alignment approach to transpose chroma features within each mode to a reference (but unknown) tonic. Then several methods, including Single Profile Correlation, Multiple Profile Correlation and Support Vector Machine, are exploited to address mode learning and classification. Experimental results show the feasibility of the proposed approach.