SoundSuggest is a visual explanation system. Such a system uses visual elements to explain and provide insight into a complex concept. The concept in this case is the Last.fm recommender. The goal of this explanation system is to provide insight into the quality of Last.fm item recommendations. By providing an approximation of the underlying concept of CF-based recommendation, the user can make an estimation of how the system calculated this recommendation. The extension becomes active on the page http://www.last.fm/home/recs if you are logged in with your account. Note that you'll need to authenticate the application the first time you visit the page.