From Gaspar Sanz' "MUSICAL INSTRUCTION ON THE SPANISH GUITAR" published in 1674 :
The Italians, French, and people of other nations classify the guitar as Spanish. The reason is that in ancient times it used to have no more than four strings, and then in Madrid, Maestro Espinel, a Spaniard, added a fifth to it, and thereby its perfection was attained. The French, Italians, and people of other nations, in imitation of us, also added the fifth course to their guitar, and therefore they call it the "Spanish guitar".
Others have discussed the perfection of this instrument, some saying that the guitar is a perfect instrument, and others that it is not. I take the middle way, and declare that it is neither perfect, nor imperfect, but what you make it, since the fault or imperfection is in him who plays it and not in the instrument itself; for on one single string without frets I have seen many feats performed for which others would require the registers of an organ. Therefore, each player must make the guitar either good or bad, since it is like a lady, but to whom the saying "look at me but do not touch me" does not apply, and its rose is quite different from a real rose, since it will not wither however much it is touched with the hands, and moreover, if it is plucked by the hands of a skilled master, it will produce in them an ever-new bouquet which delight the ear with their sonorous fragrances.
