Shazam is one of the most impressive apps created to identify what track or song you're listening to. This video explains how the service takes small fragments of music recorded by users for identification and references a phenomenal catalog of existing productions.
It works using scatter plots, which identify the transients in the song - rather than the actual harmonic content, as shown on a spectrogram. Genius!
https://www.shazam.com/gb/home
About the author [midierror]: midierror makes nifty Max For Live devices, innovative music hardware, award winning sample packs and hosts a podcast speaking to people in the music world.
Older Music Machines & the People Who Still Use Them