For years audiophiles have tried to persuade more casual music fans that a vinyl record played on a decent sound system sounds better than a digital recording played on the same system.
The former continues to use the CDDB format for its database, whereas MusicBrainz made a fresh start and completely revamped their digitalmusic metadata format and system.
When a user with a mobile phone inputs 15 seconds of music, the system creates a digital signature for that snippet and then looks for a matching pattern in the database.