Declaracionde Instrumentos Musicales by Juan Bermudo also shows a 7 string version, although only fragmants of music for the 7 stringed instrument survive from that time.
Luis Milan's El Maestro
Luis Milan's El Maestro, published in 1535, was the 1st book about the vihuela de mano, an early guitar. An illistration in it shows an instrument shaped like a guitar with six courses of strings, tuned like a lute.
Guitar books Published between 1596 - 1750 in Spain or Naples.
1596 - 1714
J.C. Amat: 1596, 1626, 1627, 1639, 1745, 1750.
N. Doizi: 1640, 1645.
G. Sanz: 1674, 1675, 1697.
L. Ruiz de Ribayaz: 1677.
F. Guerau: 1694.
D. de Murcia: 1714.
1600 - 1750
A string instrument with five courses of gut strings and moveable gut frets. The first (highest pitched) course was often a single string
G. P. Foscarini
Published in 1629, 1630, 1632, 1640 (2 editions), 1649.
1631, 1635, 1661, 1676.
French guitar music
Frencg guitar music was made for Isabel Van Langenhove. It can still be found in Holland (Amsterdam, University Library).
G. B. Abbatessa
1635, 1637, 1650, 1652
Allelande & Sarabande
The 1st important guitar composer of the seventeenth century worked as a guitarist, lutenist, and a theorbist in his native Italy.