1. A method comprising: receiving, at a computing device, a metadata request, which comprises a plurality of numeric values retrieved from a media item, as metadata corresponding to the media item; in response to the metadata request, first querying first and second metadata sources using the received metadata, so as to retrieve at least one primary record; transmitting the at least one primary record in response to the metadata request; in response to the metadata request and to extracting no metadata from one of the metadata sources queried using the first query, performing a second query of the queried metadata source, the second query formed using metadata extracted from the at least one primary record as other metadata corresponding to the media item, so as to retrieve, using the second query and the other metadata, at least one secondary record from the queried metadata source; transmitting the at least one secondary record in response to the metadata request; creating, at the computing device, a linking record associating the other metadata extracted from the primary record with the metadata received with the metadata request; and storing the linking record in a linking database that is in communication with the computing device.