The best information I found regarding the evolution of the modern guitar is the 2002 (or later) revision of “The Guitar And Its Music – From the Renaissance to the Classical Era by James Tyler and Paul Sparks” available from Los Angeles Classical Guitars and other places. It’s an expensive book, but it contains vast research and is packed with detailed information. It is a serious academic work which provides new, primary source information and dispels many myths about the guitar. Two-thirds of the book is an update of an earlier book, “The Early Guitar” which details the 4-course and 5-course guitar, as well as some discussion of the vihuela and lute. This background is necessary to understand how the 6-string guitar arose. The latter third of the book is by Paul Sparks, titled “The Origins of the Classical Guitar” which specifically details the invention and evolution of the 6-string modern guitar from 1750-1800. “Additional research of the guitar’s history from the 1750′s to 1800′s examines how the five-course guitar gradually gave way to the six-string instrument, a fascinating process that occurred in different ways and times in France, Italy, Spain, Germany and Britain. – LACG.” I shall refer to the ground-breaking and excellent research by Tyler & Sparks throughout this page, which is based largely on their ideas. Anyone wanting to learn more about this topic should read the book. It has turned conventional thinking upside-down and I have completely re-thought the guitar’s place in history as a result of this book. Key...