ABSTRACT
Essential aspects of music may be summarized under the keywords “structure”, “information” and “communication”. Even aleatoric pieces where events are generated randomly (e.g. Cage, Xenakis, Lutoslawsky) have structure and information induced by the definition of specific random distributions. It is therefore meaningful to measure the amount of structure and information contained in a composition. Clearly, this is a nontrivial task and many different, and possibly controversial, definitions can be invented. In this chapter, two types of measures are discussed: 1) general global measures of information or randomness, and 2) specific local measures indicating metric, melodic, and harmonic structures.
