The purpose of this study was to carry out a comparison between references to articles published in the Journal of Music Therapy before December 2002 identified through searching PubMed/MEDLINE, the Ingenta database and those actually published in the journal. To carry out this comparison we have created a new database, called the Music Therapy World Journal Index, which includes complete indexes of selected music therapy journals. All articles published in the Journal of Music Therapy since its commencement in 1964 are referenced in this database. We found a large number of articles that are not identified by searching PubMed/MEDLINE. There is an under-representation of both the amount of articles published in this journal and in the range of areas for clinical application and research in music therapy. The Ingenta database is comprehensive but limited in its coverage of the early years. To carry out a comprehensive research of the literature, it is necessary to consult an expert database, such as the Music Therapy World Journal Index, that guarantees an unequivocal level of completeness.