Devices and methods are disclosed for providing references to client devices. In one aspect a method includes storing, on a storage device, a plurality of references, each of the plurality references identifying a location of a media track file containing a media track. The plurality of references include a first reference identifying a first location of a first media track file. The method further includes storing, on the storage device, a playability rating for each of the plurality of references, updating the playability rating for the first reference based on an elapsed time for a first client device to receive a predetermined portion of the first media track file, and excluding the first reference from a selection of the plurality of references, in response to determining the playability rating for the first reference is below a threshold playability rating. Other devices, methods and computer program products are also disclosed.