The main categories and subcategories are listed as follows:
- Category:Composers umbrella category: not for individual articles
- Category:Composers by nationality umbrella category
- Category:Composers by instrument umbrella category
- Category:Classical composers umbrella category
- Category:Medieval composers banners June 2008
- Category:Trecento composers banners June 2008
- Category:Quattrocento composers banners June 2008
- Category:Renaissance composers banners June 2008
- Category:Baroque composers banners June 2008
- Category:Classical-period composers banners June 2008
- Category:Romantic composers banners June 2008
- Category:20th century classical composers banners June 2008
- Category:Experimental composers banners June 2008
- Category:Modernist composers banners June 2008
- Category:Neoclassical composers banners June 2008
- Category:Postmodern composers banners June 2008
- Category:21st-century classical composers banners June 2008
- Category:Women classical composers banners June 2008
- Category:Medieval composers banners June 2008
- Category:Ancient music composers banners June 2008
- Category:Byzantine composers banners June 2008
- Category:Fictional composers banners June 2008
- Category:Light music composers banners June 2008
- Category:Lists of composers
- Category:Women composers
Categories outside the scope of the project are:
- Category:Anime composers (Anime and Manga Project)
- Category:Ballet composers (Ballet Project)
- Category:Film score composers (Film Music Project)
- Category:Jazz composers (Jazz Project)
- Category:Musical theatre composers (Musical Theatre Project)
- Category:Opera composers (Opera Project)
- Category:Songwriters (mixed category of composers and writers)
All articles with Composers Project banners are in Category:WikiProject Composers articles. Articles that also have stub templates are in Category:Stub-Class Composers articles.