CHIAROSCURO: Bright and Dark. The result of laryngeal source and the resonating system interacting in such a way as to present a spectrum of harmonics perceived by the listener as a resonant BALANCED VOCAL QUALITY. #openthroat
The first time the term CHIAROSCURO appears is in 1774 in Mancini's treatise "Practical Reflections of the Figurative Art of Singing". Prior to this, other authors eluded to this tone quality but never used a specific term.
In 1592, Zacconi writes of his preference for the bright ringing chest, not dull voices. What Zacconi was describing was firm glottal closure (bright clear ringing sound) versus weak and airy sounds (Dull sound). Caccini reinforced Zacconi's statement in his Le Nuove Musiche which was published in 1602. A few years later in 1619, Praetorius translated Caccini's Le Nuove Musiche into German. We begin to see German authors echoing the same thoughts on vocal tone production and registers.
Basically, it was Manuel Garcia II who attempted to explain tone quality. Garcia stated the quality of clear and bright tones in produced by firm glottal closure. The dark or warm quality of the tone is produced by the laryngeal tube length. He proved his statements with his Laryngoscope. Garcia never used the term CHIAROSCURO, but his findings are exactly in line with the writings of Mancini and Lamperti: AKA the Italian School of Singing.