Other
Baroque Cantata
If information is needed about Baroque cantatas, this site can probably provide it. Ccmposer biographies and audio samples of their cantatas are included in the site. There is also great information about the Baroque era in general.
Other
Use of Vibrato in Baroque Vocal Music
As the title indicates, this site focuses on Baroque vibrato. The thoroughness of the research is impressive, yet it reads easily and is not difficult to absorb.