This paper is showing the importance of music and music collections in a way that has contributed to the treatment of music therapy. The topic of the paper includes a brief overview of the emergence of music and its development, how music has influenced the emergence of music collections in the world and in Croatia. A special review of the paper is on the collection of Musicals and Audio Materials of the National and University Library and on the Music Department of the Libraries of the City of Zagreb. The paper also contains an overview of previous knowledge of music therapy and its impact on humanity, his behavior and performance of certain assets. The paper examines the effect of music therapies in the treatment of patients suffering from aphasia (speech loss) and influence of music therapies in the care and nursing of the elderly - geriatrics. Also, the paper describes the effectiveness of Mozart effect in the practice of music therapy.