Six Sonatas for Violin and Harpsichord, BWV 1014–1019 alto solo. At first declamatory in the "forte" passages, the "piano" responses are expressive but subdued. Bach's knowledge of the expressive qualities of the violin is shown in the opening phrases, written so they can be played on the G string, the lowest string on the violin, regarded as having a "noble" tone. As explains, citing the opening of BWV 1017/3 as an example, the G string's "energy and powerful voice make it a whole instrument in itself and the lower this voice is, the more opportunity it gives to expression to attain the sublime." Around the violin melody, in
Viol for the lowest-pitched bass strings on viols, and on many other string instruments as well. Viols are fretted in a manner similar to early guitars or lutes, by means of movable wrapped-around and tied-on gut frets. A low seventh string was supposedly added in France to the bass viol by Monsieur de Sainte-Colombe (c. 1640–1690), whose students included the French gamba virtuoso and composer Marin Marais. Also, the painting (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