How to tag classical mp3 files

Basic Guidelines

• The Artist should contain just the composer not the performer. For details, see below and ClassicalReleaseArtistStyle. 
• The ReleaseTitle should include the title of the release followed by the major performer (i.e. the name of orchestra or quartet) inside parenthesis. For details, see below and ClassicalReleaseTitleStyle 
• The TrackTitle should contain the overall work (name of the symphony etc.) followed by ':' and then the actual name of that movement. For details, see below and ClassicalTrackTitleStyle 
• Convert the release to a VariousArtistsRelease if it contains works by more than one composer (see ConvertReleaseToMultipleArtistsEdit and ClassicalReleaseArtistStyle). 

http://musicbrainz.org/doc/Classical_Style_Guide