As a music teacher, student and nut I'm always on the lookout for good quality music sites that teach, are fun or just have good information. Below is a list of my favorites. Webmasters, if you see your site listed below and you want it removed for whatever reason, please email me and let me know.
Composers and General Information
http://www.classicalarchives.com/ - features midi backing tracks and information about composers. Can be used for free, though more information and tracks available if you pay
http://www.sesk.org/Aesthetics/Music/Baroque.htm- THE BEST SITE FOR INFORMATION ON THE BAROQUE. EASY TO UNDERSTAND AND REMEMBER!!
http://myweb.tiscali.co.uk/franzschubert/life/index.html- the ultimate Schubert site with quotes, family tree, backing tracks, works composed etc
http://www.bachcentral.com/artofug.html - Good site for JS Bach
http://www.soweirdproductions.com/?page_id=112 Information about the Baroque period, tips on composition, main composers of the time
http://www.recmusic.org/lieder/ - information site about Lieder and Art songs.
http://www.schubertline.co.uk/home.htm- a site dedicated to arias, French art song and Lieder, good but you do have to pay
http://www.kunstderfuge.com/ - another really good site featuring information on composers and midi tracks of their works. Great for Virginal music and Renaissance. Special interest on historical development of fugues
http://www.classical.net/music/links/midiarch.html- one site with links to many other sites guitar tabs, free piano music, backing tracks
http://www.mymusictools.com/- a site dedicated to the computer / software side of music, ie recording, manipulation, converting between different formats. A fun and geeky site
http://www.ipl.org/div/mushist/index.html#class site with easy to digest information on all the periods of music and key figures
http://www.dolmetsch.com/musictheory23.htm- comprehensive analysis of ornamentation throughout the ages for various instruments
http://www.triviaplaza.com/trivia.php?quiz=classical-music-composer a great site for quizzing yourself on composer knowledge
http://www.actionquiz.com/quiz.php?trivia=classical-music Easy or Hard, go up against other people to see who knows more about what composers wrote.
Sites for Children
http://www.8notes.com/ - a music site that is aimed at children and professionals with sections for composers, time periods, music jokes, music theory, online tests and games, printable blank music pages, midi converter (converts midi sounds into readable music), sections for instruments an excellent site!!
http://www.dsokids.com/2001/rooms/musicroom.asp- another music site aimed for children, has a music encyclopaedia, information on the orchestra
http://www.melodyfactory.com.au/kids_new.htmmusic site specifically for children with information about instruments, music dictionary, what instruments form typical bands
http://www.classicalandjazz.co.uk/Dictionary/A.htm- musical dictionary online
http://www.musictheory.net/- great site for children and older learners to test their knowledge, practice their aural work
http://resources.kaboose.com/games/music.html- bright and fun interactive childrens music site with games and aural training. A really great site for younger children
http://www.ababasoft.com/music/ - a site with various links for theory, aural training etc
Sites for Singers
http://www.allaboutopera.com/ - great site for operas synopsis of operas, where they are playing
http://www.vocalist.org/index.html- site for singers and singing teachers with hints and tips for performance, links to backing sites
http://www.mta.ca/music/academics/disklavier/index.html- good for singers as it features accompaniment for many popular arias.
http://www.classicalmidiconnection.com/cmc/index.html- an excellent resource for singers that has music classed by composers in alphabetical order or you can search via time period. All backing tracks are free
http://www.aria-database.com/links.html- Aria database with lyrics, translations, midi backing tracks, production companies and composers GREAT FOR SINGERS
PHEW that's it