MX structural metadata as MIR tools

In this paper two main topics are covered: a new model for melodic fragments or indexes and its embedding in MX, the new XML-based format currently undergoing the IEEE standardization process, in order to take advantage of its structural layer in a MIR-oriented perspective. Our goal is to show how music information retrieval methods can be improved by the use of particular melodic invariants coming from graph theoretic tools applied to melodies in order to catch more musical transformations than other methods as, for example, permutations of subfragments. This approach to the melodic similarity problem leads to associate a musical graph to each melodic segment in order to extract MIR-useful invariant quantities.