When food enters from esophagus, one of the functions of the stomach is to produce and release enzymes. These enzymes help in the digestive mechanism. The pH here is two (2) that provides the optimum acidity environment for the maximum activity of pepsin, a protein-digesting enzyme.
The clavichord is a European stringed keyboard instrument known from the late Medieval, through the Renaissance, Baroque and Classical eras. Historically, it was mostly used as a practice instrument and as an aid to composition, not being loud enough for larger performances. The clavichord produces sound by striking brass or iron strings with small metal blades called tangents. Vibrations are transmitted through the bridge(s) to the soundboard.
To play a note on the clavichord a key is pressed down. This makes the other end of the key (inside the instrument) comes up (like a see-saw). That end has a thin metal blade called a tangent which hits the string. The tangent stays on the string until the player takes his finger off the key.