definition-rules · pachet2001-harmonization-constraints

This problem, which consists in creating musical scores which satisfy given rules of harmony, has been the object of numerous studies, most of them using constraint techniques in one way or another. [...] automatic harmonization, i.e. the problem of producing musical arrangements (scores) from given melodies [...] In this survey we focus on tonal music [...]. They are mainly specifications of forbidden combinations of notes [...]. Finally, respecting the rules does not guaranty that the result will be musically meaningful or interesting. To make an analogy with language, harmonic rules can be considered as merely syntactic. [...] four-voice music [...] (the soprano (highest), alto, tenor and bass (lowest)). [...] each melody has a given range [...]. Additionally, a rule states that voices should never cross each another. [...] several intervals between notes are forbidden, such as the tritone interval [...]. This rule states that between two successive chords there should not be a parallel fifth. [...] Other similar rules apply to parallel octaves or unison intervals.