Strings (tennis)
In tennis, the strings are the part of a tennis racquet which make contact with the ball. The strings form a woven network inside the head (or "hoop") of the racquet. Strings have been made with a variety of materials and possess varying properties that have been measured, such as dynamic stiffness, tension retention, thickness (gauge), string texture (shape of the string), and rebound efficiency.
Michael Masley
The lid can be flexed, which will bend the pitch. While many stringed instruments can pitch bend, others bend along only one direction, altering the pitch of only a single set of strings, and by changing the tension of all strings together, their musical interval relationships stay constant. By having two courses of strings which are not parallel, the pitch bending changes the tonal relationships between the two sets of strings. If the instrument is flexed parallel to one set of strings, that set of strings remains unaltered, but the perpendicular set of strings deepens in pitch. If the instrument is flexed at an angle to both sets of strings, the pitch of both sets varies in a mathematically related fashion. Past a certain degree of flex, the two courses of strings touch and dampen each other, and the sounds produced by the spring dominate.