Query by humming (QBH) is a music retrieval system that branches off the original classification systems of title, artist, composer, and genre. The system involves taking a user-hummed melody (input query) and comparing it to an existing Database. The system then returns a ranked list of music closest to the input query.

For the mass public this system means an iPod with a built-in microphone that allows for faster searching through MP3 files.

= External links =