From MusicBrainz Wiki
AcoustID is an audio fingerprinting solution built entirely on open-source technology. It was integrated into MusicBrainz Picard since version 0.16.
How to Configure Picard
- Go to Options → Advanced → Fingerpriting, select Use AcoustID.
- Download fpcalc for your platform from the Chromaprint download page.
- Enter the path to the unzipped fpcalc tool into the Fingerprinter field.
- Clicking Scan in the main windows will now use AcoustID for fingerprint lookups.