bass viol by Monsieur de Sainte-Colombe (c. 1640–1690), whose students included the French gamba virtuoso and composer Marin Marais. Also, the painting Saint Cecilia with an Angel (1618) by Domenichino (1581–1641) shows what may be a seven-string viol. Unlike members of the violin family, which are tuned in fifths, viols are usually tuned in fourths with a major third in the middle, mirroring the tuning employed on the vihuela de mano and lute during the 16th century and similar to that of the modern six-string guitar. Viols were first constructed much like the vihuela de mano, with all surfaces, top, back, and sides made from flat slabs or pieces of joined wood, bent or curved as required. However, some viols, both early and later, had carved tops, similar to those more commonly associated with instruments of the violin family. The ribs or sides of early viols were usually quite shallow, reflecting more the construction of their plucked vihuela counterparts. Rib depth increased during the 16th century, finally coming to resemble the greater depth of the classic 17th-century pattern. The flat backs of most viols have a sharply angled break or canted bend in their surface close to where the neck meets the body. This serves to taper the back (and overall body depth) at its upper end to meet the back of the neck joint flush with its heel. Traditional construction uses animal glue, and internal joints are often reinforced with strips of either linen or vellum soaked in hot animal glue—a practice also employed in early plucked vihuela construction. The peg boxes of viols (which hold the tuning pegs) were typically decorated either with elaborately carved heads of animals or people or with the now-familiar spiral scroll finial. The earliest vihuelas and viols, both plucked and bowed, all had sharp cuts to their waists, similar to the profile of a modern violin. This is a key and new feature—first appearing in the mid-15th century—and from then on, it was employed on many different types of string instruments. This feature is also key in seeing and understanding the connection between the plucked and bowed versions of early vihuelas. If one were to go searching for very early viols with smooth-curved figure-eight bodies, like those found on the only slightly later plucked vihuelas and the modern guitar, they would be out of luck. By the mid-16th century, however, "guitar-shaped" viols were