Original sentence: In 1824 Graf delivered to Ludwig van Beethoven a 6 1/2-octave piano triple-strung to C#, and quadruple-strung from D to the top (F4) -- possibly on the assumption that this stringing would make the piano more audible for the composer, who was quite deaf by this time
Edited sentence: Graf achieved this result by a variety of means.In 1824 Graf lent to Ludwig van Beethoven a 6 1/2-octave piano triple-strung to C#, and quadruple-strung from D to the top (F4) -- possibly on the assumption that this stringing would make the piano more audible for the composer, who was quite deaf by this time.The dampers were graded in size (larger in the bass), and used different materials for different ranges (wool in the treble, leather in the bass).The lowest 13-17 dampers were weighted with lead.The weight of the dampers was also controlled:  dampers for lower notes were made of a heavier wood (beech), vs.Viennese pianos, including Graf's, are known for effective damping of sound after the key is released.lime in the treble