In an example context of identifying live audio, an audio processor machine accesses audio data that represents a query sound and creates a spectrogram from the audio data. Each segment of the spectrogram represents a different time slice in the query sound. For each time slice, the audio processor machine determines one or more dominant frequencies and an aggregate energy value that represents a combination of all the energy for that dominant frequency and its harmonics. The machine creates a harmonogram by representing these aggregate energy values at these dominant frequencies in each time slice. The harmonogram thus may represent the strongest harmonic components within the query sound. The machine can identify the query sound by comparing its harmonogram to other harmonograms of other sounds and may respond to a user's submission of the query sound by providing an identifier of the query sound to the user.