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
Concert pitch beginning with the work of German physicist Johann Scheibler in the 1830s. The term formerly used for the unit of pitch, cycle per second (CPS) was renamed the hertz (Hz) in the 20th century in honor of Heinrich Hertz. During historical periods when instrumental music rose in prominence (relative to the voice), there was a continuous tendency for pitch levels to rise. This "pitch inflation" seemed largely a product of instrumentalists competing with each other, each attempting to produce a brighter, more "brilliant", sound than that of their rivals. (In string instruments, this is not all acoustic illusion: when tuned