John Dowland http://www.hoasm.org/IVM/Dowland.html
A biography of one of England’s greatest composers for the lute, with a handful of links to other Dowland-related information.
Giovanni Gabrieli http://www.goldbergweb.com/en/history/composers/10946.php
Giovanni Gabrieli’s life and career straddled the intersection between the Renaissance and the Baroque era. This site provides a basic biography and image of the composer, as well as a discography (though the list also contains recordings that do not contain his music) and a list of articles that make mention of the composer.
http://www.hoasm.org/IVN/GabrieliGiovanni.html
Another biography and discussion of the composer, with links to a partial discography of his music and to a discussion of the Venetian polychoral style of composition.
Hildegard von Bingen http://www.isi.edu/~lerman/music/Hildegard.html
Hildegard von Bingen was a 12th-century nun, composer and mystic. This site provides an excellent discussion of her life, including the likely medical condition behind her visions, as well as a bibliography, discography and glossary.
Josquin des Prez http://w3.rz-berlin.mpg.de/cmp/josquin.html
Josquin des Prez was certainly one of the greatest composers of the Renaissance. This website offers a good basic biography and a general discussion of his compositions.
Orlandus Lassus http://www.hoasm.org/IVK/Lassus.html
Orlandus Lassus was one of the major composers during the Renaissance. This webpage offers a biography and a discussion of his music.
Guillaume de Machaut http://w3.rz-berlin.mpg.de/cmp/machaut.html
Guillaume de Machaut was one of the more important composers of the Medieval era, and is remembered in particular for his setting of the Ordinary of the Catholic Mass. This site offers a biography and image of the composer.
http://www.medieval.org/emfaq/composers/machaut.html
Another, more in-depth biography of the composer, this site also includes an extensive discography of his works, as well as the complete texts (not translated into English, unfortunately) of all his vocal compositions.
Giovanni Pierluigi da Palestrina http://w3.rz-berlin.mpg.de/cmp/palestrina.html
Giovanni Pierluigi da Palestrina is another of the great composers of the Renaissance, and this website offers a brief biography of his life, including how his music was chosen to become the model what Catholic Counter-Reformation music should be.
Tomás Luis de Victoria http://www.hoasm.org/IVL/Victoria.html
Tomás Luis de Victoria was arguably Spain’s greatest Renaissance composer. This webpage offers a biography and discussion of his music, as well as a partial discography.
Performers
The King’s Singers http://www.kingssingers.com/
The official website for this world-renown vocal ensemble, visitors will find a history of the group as well as individual members’ biographies, a list of current performances, audio samples, a discography, photographs, and much more.
Jakob Lindberg http://www.musicamano.com/
Jakob Lindberg is a Swedish lutenist who performs worldwide, as well as teaches at the Royal College of Music in London. This is his official website, offering a biography, a discography with audio examples, photographs and descriptions of his instruments, photographs of Lindberg, and more.
Tallis Scholars http://www.thetallisscholars.co.uk/
The Tallis Scholars are renowned for their recordings of music from the Renaissance. This, their official website, offers current tour dates, a biography of the ensemble and its director, Peter Phillips, photographs, and more.
Miscellaneous
Gregorian Chant http://www.solesmes.com/anglais/gregorian/greg_home.html#forme
The choir of the Abbey of Solesmes is one of the premiere groups to record Gregorian chant, having produced some 16 albums, beginning in 1952. This is the Abbey’s website, which provides a wide variety of information about the Abbey. To learn more about Gregorian chant, hover your mouse over the photograph labeled “Gregorian.” A pop-up menu then allows you to learn more about either the history or the forms of Gregorian chant. Contained in the latter page is a description of how the chant is used in the worship liturgies of the Catholic Church. Audio files are included, though they are in the relatively uncommon .ogg format, which is not recognized by many of the most popular audio-playback programs. There are a number of programs that do play this format, though; one such player that is available for Windows, Mac OS X and other platforms is VLC (http://www.videolan.org/vlc/).
A Guide to Medieval and Renaissance Instruments http://www.music.iastate.edu/antiqua/instrumt.html
This site offers photographs, descriptions, and audio examples of a wide variety of musical instruments from the Medieval and Renaissance eras.
Medieval Music: Birth of Polyphony http://www.stanford.edu/~jrdx/medieval.html
An excellent non-technical introduction to sacred Christian music from its birth to the rise of polyphony during the Medieval era.
Motet http://w3.rz-berlin.mpg.de/cmp/g_motet.html
This webpage provides a further discussion and history of the motet, though the language used is rather technical. However, there are hyperlinks to definitions and discussions of many of the important terms and composers contained in this page.
http://www.newadvent.org/cathen/10600c.htm
From the Catholic Encyclopedia, this article offers a somewhat more in-depth discussion of the motet, though without as much technical language. Hyperlinks are provided to some of the important composers of this musical form.