A user interface generator is configured to access a media file that stores acoustic data representative of sounds. The user interface generator determines a mood category of the media file, based on a mood vector calculated from the acoustic data. The mood category characterizes the media file as being evocative of a mood described by the mood category. The user interface generator generates a user interface that depicts a grid or map (e.g., a “mood grid” or a “mood map”) of multiple zones. One of the zones may occupy a position in the grid or map that corresponds to the mood category. The user interface may then be presented by the user interface generator (e.g., to a user). In the presented user interface, the zone that corresponds to the mood category may be operable (e.g., by the user) to perform one or more actions pertinent to the mood category.