In the last ten years, our ways to listen to music have drastically changed: In earlier times, we went to record stores or had to use low bit-rate audio coding to get some music and to store it on PCs. Nowadays, millions of songs are within reach via on-line distributors. Some music lovers already got terabytes of music on their hard disc. Users are now no longer desparate to get music, but to select, to find the music they love. A number of technologies has been developed to adress these new requirements. There are techniques to identify music and ways to search for music. Recommendation today is a hot topic as well as organizing music into playlists.