An exemplary method includes providing a music collection of a particular scale, determining a distance parameter for locality sensitive hashing based at least in part on the scale of the music collection and constructing an index for the music collection. Another exemplary method includes providing a song, extracting snippets from the song, analyzing time-varying timbre characteristics of the snippets and constructing one or more queries based on the analyzing. Such exemplary methods may be implemented by a portable device configured to maintain an index, to perform searches based on selected songs or portions of songs and to generate playlists from search results. Other exemplary methods, devices, systems, etc., are also disclosed.