A digital music player includes an audio file selector that selects a subsequent audio file to play from a collection of audio files based upon a desired relationship between an audio characteristic of a current audio file and an audio characteristic of the subsequent audio file. The audio selector digitally analyzes the audio files to determine their audio characteristics. A weighting procedure then assigns weights to the audio files in the collection based upon their audio characteristics and their relationship to the audio characteristics of the current audio file. A random selector then pseudo randomly selects the subsequent audio files from a weighted list of the files. The desired relationship can be a specified correspondence between a key or tempo of the current audio file and a key or tempo of the subsequent audio file. The audio selector is preferably implemented through a software macro which is downloaded into an existing digital music player.