The Aria Database  (http://www.aria-database.com)
This database has a diverse collection of over 1000 operatic arias, and includes translations, aria text, and a collection of MIDI files of operatic ensembles and arias. 

The Classical Music Pages (http://w3.rz-berlin.mpg.de/cmp/)
At this site, you can access composers by name, musical form, or musical epoch. You can also access instruments by name or find definition of a variety of musical terms. Links to a number of excellent reference sites.

Gemm Music (http://www.gemm.com)
This site has the world's largest music catalog! Search from 19 million CDs, LPs, 45s and more from thousands of sellers around the world! Includes Hard to Find • Rare• Out of Print • Collectible Import • Discount • Used •Independent Artist & Label  

International Lyrics Server (http://www.lyrics.ch)
Only know a few words of a Beatles song but not sure of the title? You need this site! Contains excess of 60,000 lyrics searchable by artist, album and song title. 

Music Yellow Pages (http://www.musicyellowpages.com/ypdirect.htm)
Access to addresses and phone numbers of vendors of music products from accessories to xylophones. 

MUSICA  (http://www.musicanet.org)
MUSICA's goal is to gather information on all choral music of the world and become a virtual multimedia library.  MUSICA's database is multilingual, and contains over 73,000 references. 

Musicals.net (http://musicals.net)
The source for musical theater information. Offers a list of 60 or so musicals in alphabetical order. For each, you can view a synopsis, lyrics, links, and more. NOTE: Treatments of new musicals are far sketchier than treatments of the classics. 

Newburgh Free Library:  Music  (http://www.newburghlibrary.org/websites/music.htm)
Newburgh Free Library's collection of music links divided by subject. 

Operabase  (http://www.operabase.com/en/)
Has a great deal of good links including performance and artist searches, opera timelines, and it is also multilingual. 

Rolling Stone (http://www.rollingstone.com) 
An A - Z biographical listing of rock musicians, plus articles and highlights from the latest issue of the magazine. 

Sheet Music Plus  (http://www.sheetmusicplus.com)
Good place to look for all types of sheet music. 

Worldwide Internet Music Resources (http://www.music.indiana.edu/music_resources)
Another good metasite from the Indiana University of Music. Useful composer and music journal links.