Content-Based Indexing of Symbolic Music Documents

Indexing is the core component of most information retrieval systems, because it allows for a compact representation of the content of a collection of documents, aimed at efficient and scalable access and retrieval. Indexing techniques can be extended also to music, providing that significant descriptors are computed from music documents. These descriptors can be defined as the \u201clexical units\u201d of music, and depend on the dimensions that are taken into account \u2013 melody, harmony, rhythm, timbre \u2013 and are related to the way listeners perceive music. This paper describes some relevant aspects of indexing of symbolic music documents, giving a review of its basic concepts and going in more detail about some key aspects, such as the consistency at which candidate index terms are perceived by listeners, the effectiveness of alternative approaches to compute indexes, and how individual indexing schemes can be combined together by applying data fusion approaches