Music Genie refers to audio processing technologies for quick and easy music browsing and discovery. We built research prototype software that allows users to quickly generate playlists from a collection of thousands of songs. Our software provides an interactive, content-adaptive, thumbnail-based presentation of music. The software accepts user inputs interactively during use, and it consecutively presents short music thumbnails for quick browsing. This direct, interactive presentation of music makes our system simple and transparent for users. Unobstrusively, the user's interactions (or lack thereof) are input into a real time system that, based on the prior analysis of the music content, adaptively presents a potentially interesting new song thumbnail. This technology may be used to 1) assist users discover music for purchase from a web music store; 2) allow users to browse their PC music collection based on current taste; and 3) allow intelligent browsing, playback or playlist generation in small, interface-limited, music players.