SoundSieve is an exciting new way to look at the structure of music, designed to create a visual �fingerprint that can provide the listener with instant information about any given piece. SoundSieve aims to counter the trend towards overly simplistic, flashy music visualization programs by creating a real-time visualization that is not only informative, but enlightening as to the underlying musical structure of the piece. From any MP3 file, SoundSieve uses simple, intuitive mapping to create a picture and video playback that highlight key audio features. In addition, SoundSieve allows the user to actively examine the piece: to zoom in on portions of interest, adjust playback, and add informative overlays. SoundSieve has recently been used to create customized animations that highlight particular features in a piece (e.g., Tod Machover�s "The System" for the opera "Death and the Powers").