Systems and techniques are provided for finding differences in nearly-identical audio recordings. A first version of an audio recording may be received. A second version of the audio recording may be received. A difference between the first version of the audio recording and the second version of the audio recording may be determined using time domain analysis and frequency domain analysis. The difference may be stored in a difference set. The difference set may allow the first version of the audio recording to be distinguished from the second version of the audio recording. The audio recording may be a music track. The first version of the audio recording may be an explicit version of the music track. The second version of the audio recording may be an edited version of the music track.