Three different ways of tuning the guitar are well documented in seventeenth-century sources as set out in the following table. This includes the names of composers who are associated with each method. Very few sources

Matteo Salas (1600s).
Antonio Stradivari (1644–1737). Of his five surviving guitars, the 1679 "Sabionari" is the only one in playable condition. It is the solo instrument on more than a dozen videos at YouTube.com. Two other Stradivari guitars are in

• Lex Eisenhardt, Italian Guitar Music of the Seventeenth Century, University of Rochester Press, 2015.
• Lex Eisenhardt, "Bourdons as Usual". In

• Giovanni Paolo Foscarini (c.1600 - 1650), I quattro libri della chitarra spagnola (c.1635) [1]
• Francesco Corbetta (1615–1681), Varii scherzi di sonate, Libro 4 (c.1648) [2]
• Angelo Michele Bartolotti (c.1615-1680)

• David Ryckaert III (Antwerp 1612–1661)
• Lex Eisenhardt
• Eduardo Egüez
• Paul O'Dette

• Technique "Baroque guitar for the modern performer - a practical compromise", by Don Rowe and Richard d’A Jensen