I think they're called genres. Forms and genres are styles. Style is anything a piece can identify with. Style of a period, style of an individual, style of a form, style of a genre.
Forms are stripped of meanings that don't pertain to structure. Such as binary, arch, fugue. Genres generally carry emotional/functional/rhythmic/poetic connotations. But they can be structural at times owing to traditional associations. Some terms are purely configurational.