In music an exposition is the first of the sections in sonata allegro form. It usually presents two contrasting themes, the first in the tonic key, the second in a related one (perhaps the dominant or relative major). See: sonata form.
This is a disambiguation page; that is, one that just points to other pages that might otherwise have the same name. If you followed a link here, you might want to go back and fix the link, so that it points to the appropriate page.