PBS
Classics for Kids: Musical Instruments
An A-to-Z directory of all the instruments and tools of the orchestra. Each entry includes a description, a picture, and a sound sample.
Other
Kitchen Musician Site: What Is a Hammered Dulcimer?
Here you can find a very thorough description of a hammered dulcimer, tracing this instruments creation and history. Pictures are also included.
Wikimedia
Wikipedia: Johann Christian Bach
This encyclopedia entry for Johann Christian Bach (1735-1782) describes the life and works of this composer, the 11th son of Johann Sebastian Bach.
Smithsonian Institution
National Museum of American History: A Piano Timeline
A detailed chronology of the piano, beginning with Bartolomeo Cristofori's invention of the pianoforte in Florence, Italy, in 1700.