end-user should be able to create TAGS for songs. include standard tags like "rock" and "soul", but allow the user to create their own tags, and use this as cross-referenced information to organize not only the user's own music collection, but also to match characteristics of other users' music or playlists. user-created tags would allow Spotify to recommend more musically accurate songs, as the characteristics and style of the songs have been peer-reviewed. it's no secret that Spotify radio is weak. Utilize the social network of Spotify by tapping into the users' knowledge and experience of music.
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