Who is both the author of "A Treatise on the Fundamental Principles of Violin Playing" as well as the father of Wolfgang Amadeus Mozart?
Versuch einer gründlichen Violinschule: Versuch einer gründlichen Violinschule ("A Treatise on the Fundamental Principles of Violin Playing") is a textbook for instruction in the violin, published by Leopold Mozart in 1756. Leopold Mozart:  Mozart is best known today as the father and teacher of Wolfgang Amadeus Mozart, and for his violin textbook "Versuch einer gründlichen Violinschule".
Leopold Mozart