Justin and I have been working on our tutorial on using visualizations for music discovery to be presented ISMIR 2009. One part of this tutorial will be a survey of current commercial and research-oriented systems that use visualization to help people explore for and discover new music. Ultimately we hope to build a comprehensive web directory of these visualization as part of the supplementary material for the tutorial. We could use your help building this directory. If you know of an interesting visualization that is used for music discovery (or even a technique that you think *could* be used for music discovery), add a link/description in the comments on this post or send me an email at firstname.lastname@example.org. Thanks much!