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
Violin technique intervals of perfect fifths by bowing them in pairs. This puts the open strings in just intonation, which means the lower strings may sound flat compared to their nominal equal-tempered equivalents. In practice, this means some compromises must be made, and the strings not always tuned in perfect fifths, particularly on the viola and cello, where the lowest string is the C, three fifths away from the reference A, making the difference more apparent. Small, temporary tuning adjustments can also be made by stretching a string with the hand. A string may be flattened by pulling it above the fingerboard,