Johann Mattheson
Mattheson wrote books about music theory. He published a music periodical from 1722 to 1725. Mattheson included quotes from other musicians in this periodical. He often attacked other musicians in his writings. He did this without ever writing their names. He attacks older music styles in his writings. One of his most important works is Der vollkommene Capellmeister (English: "The Perfect Kapellmeister"). It contains things that a Kapellmeister should know.