PBS
Classics for Kids: Antonio Vivaldi
A short biography of Antonio Vivaldi (1678-1741 CE). Click to the past radio shows to hear his music and learn more about this famous composer.
PBS
Classics for Kids: Johann Sebastian Bach
A short biography of Johann Sebastian Bach (1685-1750 CE). Click to the past radio shows to hear his music and learn more about this famous composer.
On Being
Speaking of Faith: On Being: Bach's Bible
Presented is an illustrated narrative slideshow that talks about the Bible's influence on one of Bach's compositions "Mass in B Minor." [ 3:48]
Wikimedia
Wikipedia: Jean Philippe Rameau
Wikipedia offers brief biographical information on Baroque composer Jean-Philippe Rameau, including a list of works.
Other
Domenico Scarlatti: A Biographical Note
This site from BaroqueMusic.org contains a rather lengthy biography on Domenico Scarletti, musician and composer.