John Storrs' Workshop
While this is really a commercial site, it provides a lot of illustrated information on the harpsichord, the clavichord, and the spinet. The site also offers up repertoire advice, provides tips on playing, explains tuning systems, and gives information on related books and museums featuring early keyboard instruments.
Julian Rhodes' Dream Organs
This page hosts extensive accounts of the organ in literature, tracing it back to the ancient Greeks and to works by Milton. There are plans for organ design and essays on different aspects of the organ here, and even discussions on the organ in philosophy. In the literature found on this page, unusual organs and Arab organs are also treated, as well as the art of organ building.
Knowledge Haven - History of the Piano
The page provides several links to sites that offer the history of the piano. One linked site traces the history of the piano to the monochord in 1157, another to the pianoforte Christofori invented in 1709. There are also two links to a virtual gallery of pianos and a link to an article about the sociocultural factors that drove the development of the piano.
Museum of Organs
This site is devoted exclusively to housing photos of famous organs in places all over Europe and North America. Brief descriptions are included, but the main attractions are the photos of the organs themselves.
The Organ and How it Works
After touring this site in its entirety, the layman should have a pretty good idea of how the organ works. The descriptions of all organ parts and functions are helped by the extensive photo and sound files. The organ history section is extensive, classified by time period, country, and then by location. You'll learn all about the organ, and its transformation over many eras.
The Player Piano Page
This page is very useful to people who are interested in self-playing pianos. Find out about their mechanism and history of their development here, and also about music-roll artists. On a practical note, you can also buy and sell player pianos on this site, get to learn about player piano societies, and learn where to get supplies or restoration services.
The Pipe Organ
This site provides concise yet broad information on the pipe organ. It provides an overview, explains individual parts, walks you through the working of the pipes, and shows how sound is produced with them. There is even a brief but interesting history of the organ that dates all the way back to 200 B.C.
Theatre Organ Home Page
This page will help you locate theatre organs in the United States. It offers extensive and well-organized MIDI archives, some with lyrics provided, as well as bios and timelines of many organ composers. The site also supports a mailing list and classifieds ad page.
Todd Augsburger's Roller Organ Web Site
Todd Ausburger has done all he can to bring information on the roller organ to the layman. He describes with illustrations the history of this instrument, and he provides sound clips to help with the descriptions of the mechanical workings. He also maintains an enormous list of roller-organ rollers, a buying and selling page, links to restorers, and a museum of roller-organ depictions.