In 2007, the University of Arkansas Libraries received a large donation of 5,295 popular music recordings. This gift nearly doubled the existing CD holdings and greatly altered the collection's emphasis. The present authors sought to enhance retrieval in the local catalog, concentrating particularly on subject access. To this end, they analyzed popular music genre terminology used by three well-known online resources: allmusic.com, Wikipedia, and The Encyclopedia of Popular Music. This article reports their findings about the genres that each assigned to the specific artists in the collection and whether the genres were applied consistently among the three resources.In 2007, the University of Arkansas Libraries received a gift of 5,295 audio materials in the form of 3,434 CDs and CD singles and 1,861 LPs, EPs, and 45s from the estate of an alumnus. The donor had collected popular music from the late 1970s through the early 2000s. A preliminary review of the collection suggested that while the collection contained classic rock and roll, heavy metal, and blues, the donor had been particularly interested in club and dance music. Prior to the gift, the libraries' collection supported the university's curriculum and therefore almost exclusively consisted of classical music and jazz recordings. In particular, the new gift of 3,434 CDs almost doubled the existing CD collection and greatly changed its emphasis. The authors were confronted with the question of how to best identify the recordings in the collection to enhance retrieval through the library catalog.