Emms can save a “temporal bookmark” in a media file via emms-bookmarks. The file emms-bookmarks.el provides the package emms-bookmarks.
While some media is playing, invoking M-x emms-bookmarks-add will first pause the playback and then prompt for a name describing the bookmark. Tracks can have multiple bookmarks associated with them.
To jump to the next and previous bookmarks in the current track invoke M-x emms-bookmarks-next and M-x emms-bookmarks-prev respectively.
To clear all of the bookmarks for the current track invoke M-x emms-bookmarks-clear.