A method includes outputting a first graphical representation corresponding to a first group of one or more audio files and a second graphical representation corresponding to a second group of one or more audio files, wherein the first group is defined based on a respective first metadata attribute value for each audio file from the first group; receiving a user selection of the first graphical representation; and, in response to the user selection, moving the second graphical representation, thereby defining an expansion area, and outputting, within the expansion area, at least one additional graphical representation corresponding to a subgroup of the first group, wherein the subgroup is defined based at least in part on a respective second metadata attribute value for each audio file from the subgroup.