Thematic catalogue
A thematic catalogue is an index used to identify musical compositions through the citation of either the opening notes (incipit) or main theme of the work. Such catalogues can be used for many purposes, including as guides to a specific composer's works, as an inventory of a library's holding or as an advertisement of a publisher's output. In addition to the musical identification, a thematic catalogue may continue information such as dates of composition and first performance. Works within a thematic catalogue can be grouped chronologically or by genre.