1. A system for building a composite playlist comprising: a server; a plurality of session managers, each of the plurality of session managers associated with at least one of a plurality of media devices to yield associated media devices, wherein each of the plurality of session managers is configured to manage a status of one or more of the associated media devices, and wherein the plurality of session managers are configured to verify eligibility of the associated media devices to participate in a session; a playlist builder software component executable on the server configured for receiving user media item data from each of the plurality of media devices and for building a composite playlist of media data items from the user media item data; a plurality of playlist managers, each of the plurality of playlist managers associated with one of the plurality of media devices, wherein each of the plurality of playlist managers is configured to communicate with the playlist builder software component to send the user media item data of a corresponding media device to the playlist builder software component, wherein the playlist builder software component is further defined to send the media data items identified on the composite playlist to the plurality of playlist managers, and wherein the user media item data for each of the plurality of media devices is analyzed by the playlist builder software component to generate a playlist for each of the plurality of media devices to yield a generated playlist representing a media taste of a corresponding user; a recommender software component executable on the server, wherein the recommender software component is configured to access the playlist builder software component to generate a recommended mediaset responsive to the generated playlist for each of the plurality of media devices; and an aggregator software component executable on the server, wherein the aggregator software component is configured to access the playlist builder to additively generate a composite recommended mediaset responsive to the recommended mediaset generated for each of the plurality of media devices by selectively adding media data items from a plurality of the recommended mediasets, wherein media data items are selected for inclusion in the composite recommended mediaset based on a utility function that maximizes the number of users with media taste reflected in the composite recommended mediaset.