The diminutive c. 1650 Italian five-course guitar in the Austin-Marie Collection is yet another example of what scholars often refer to as a “high-A” guitar: the treble voice in a Baroque-era guitar ensemble that was tuned a 4th higher than a standard-sized instrument. Sometimes dubbed a chitarriglia, Carlo Calvi first coined the term in his 1646 publication, Intavolatura di chitarra e chitarriglia, referring to a smaller-sized, higher-pitched guitar.
As the guitar transitioned from four courses to five near the dawn of the seventeenth century, its role as an instrument for strumming, or rasgueado, differentiated it from the plucking technique, or punteado, of the vihuela. The simple raising of the third string a half step (g on a guitar vs. f# on a vihuela) easily facilitated the playing of harmonic chords. Indeed, Richard Savino, founder of the early music ensemble El Mundo and member of the Cambridge Consortium for Guitar Research, contends the guitar’s tuning convention helped pave the way for modern harmony (see part VI): https://austinmarieguitars.com/exploring-three-centuries-of-guitar-2/