MusicBrainz is a project that aims to create an open content music database. Similar to the freedb project, it was founded in response to the restrictions placed on the CDDB. However, MusicBrainz has expanded its goals to reach beyond a compact disc metadata storehouse to become a structured open online database for music. MusicBrainz captures information about artists, their recorded works, and the relationships between them. Recorded works entries capture at a minimum the album title, track titles, and the length of each track. These entries are maintained by volunteer editors who follow community written style guidelines. Recorded works can additionally store information about the release date and country, the CD ID, cover art, acoustic fingerprint, free-form annotation text and other metadata. , MusicBrainz contained information about roughly 930,000 artists, 1.4 million releases, and 14.6 million recordings. End-users can use software that communicates with MusicBrainz to add metadata tags to their digital media files, such as MP3, Ogg Vorbis or AAC.