All Music Guide (Popularity: )
http://www.allmusic.com/ Comprehensive guide to recordings in every genre. Cross-indexed source of reviews, essays, and ratings; all available online, on in-store kiosks, ...
Muze (Popularity: )
http://www.muze.com/ Longtime publisher (over 50 years) of directories of recorded music for retail stores; their data is now available for purchase ...
Trouser Press (Popularity: )
http://www.trouserpress.com/ Official site of Trouser Press magazine (1974-1984) and the Trouser Press Record Guides. Reviews and discographies from five editions of ...