All Music Guide
This is "a complete online databse of recorded music."  It has a search engine that allows searching by artist name, album title, song title, label, and musical style.  Biographies, full discographies, and album reviews are available for artists.  Essays and a glossary are provided as is a music maps features, which traces a the development of a particular style of music from other styles. 

Composer Biographies
 A site of brief biographical sketches of some of the more well-known classical composers.

The Symphony: An Interactive Guide
 The Symphony: An Interactive Guide is to provide a comprehensive resource for people wanting to expand their knowledge of the symphony - Western art music's richest and most important genre. The site features comprehensive biographies of the major symphonic composers, browseable by country or by an alphabetical list.

The Living Composers Project
"The Living Composers Project is a non-profit database begun in 2000, which aims to provide composers, listeners, performers, and researchers w ith a source of information about the music of our time.

Dr. Estrella's Incredibly Abridged Dictionary of Composers
"A chronological listing of famous composers of Western Music. Each listing contains accurate birth and death dates and the country of origin. Several of the entries also are linked to biographical essays and other sites on the web." Organized by musical period and by composer name.