Library of Congress
Loc: The Moldenhauer Archives
The Moldenhauer Archives at the Library of Congress contain approximately 3,500 items documenting the history of Western music from the medieval period through the modern era.
University of Michigan
University of Michigan: Instrument Encyclopedia: Baroque Organ
This lesson has brief info on the baroque organ and its history. You can also listen to a sound sample.
University of Michigan
University of Michigan: Instrument Encyclopedia: Baroque Violin
This brief article overviewing the history of the violin, and its role in a variety of musical genres, includes an image and references for further reading and research.
Other
Lute Harpsichord: A Forgotten Instrument
Interesting website on the lute-harpsichord, which is called "one of Bach's favorite keyboard instruments." Provides an in-depth history of this "forgotten instrument" and the ordinary lute.