Large music collections require new ways to let users interact with their music. The concept of finding ‘similar’ songs, albums, or artists provides handles to users for easy navigation and instant retrieval. This paper presents the realization and user evaluation of a music retrieval music that sorts songs on the basis of similarity to a given seed song. Similarity is based on a userweighted combination of timbre, genre, tempo, year, and mood. A conclusive user evaluation assessed the usability of the system in comparison to two control systems in which the user control of defining the similarity measure was diminished.