This smart-looking site offers a history of the pipe organ from its origin in the Middle Ages to the flowering in the baroque period. (
http://panther.bsc.edu/~jhcook/OrgHist/begin.htm
)
This site offers beautiful performances of Bach organ works on magnificent instruments. You will need to scroll pretty far down the page, past the visitors' comments, to get to the links. (
http://www.johann-sebastian-bach.org/index.html
)
This site offers a download of the complete Toccata and Fugue in D Minor by J. S. Bach, a fine performance by Frederik Magle. (
http://www.magle.dk/ubbthreads/showflat.php/cat/0/Number/51
)
On this site you can find a description of the dances in the baroque instrumental suite with sound files to help you understand the differences in them. (
http://vcenter.acaweb.org/Music/Golightly/baroquesuite/
)
This site features sound files of performances on the clavichord and allows you to compare its sound with that of the organ, harpsichord, and virginal. (
http://www.twingroves.district96.k12.il.us/Renaissance/Town/Music/Clavichord.html
)
The outline on this site offers a great overview of instrumental music in the later baroque period, including keyboard music, sonatas, and concertos. (
http://www.geocities.com/papandrew/outlines/grout11.html
)
This site describes the various forms of the baroque sonata, including sonata da camera and sonata de chiesa. (
http://w3.rz-berlin.mpg.de/cmp/g_sonata.html
)