online music database

online music database

A database of CD album information on the Internet. Music CDs do not contain artist name, album and song titles, but MP3, AAC and other compressed audio formats do (see ID3 tag). When a CD is played in the computer or is being ripped to a compressed format, the media player software queries an online database such as CDDB (www.gracenote.com), freedb (www.freedb.org) or allmusic (www.allmusic.com) to retrieve this information.

The Benefits
While a song is being played, the title is displayed on screen instead of track 1, track 2, etc. If the CD is being ripped, the titles are automatically entered into the meta-data fields of the MP3 or other compressed format. Without this service, users would have to enter the titles manually for every track in the album.

Only Track and Time
When the engineers designed the CD in the early 1980s, they never thought of reserving a couple thousand extra bytes among the 650 million available for descriptive titles. Although many think it an appalling lack of vision, the only meta-data in a CD is track number and length of track in the table of contents (TOC), which is what has been displayed on the readout of every CD player since day one. Because it would be extremely rare to have two CDs with the same number of tracks and lengths, it is precisely this data that is used to match up the album in the database. See CDDB and ripping.