 The tuning pins keep the strings tight and are held in place by friction.Steinway also employs front and rear duplex scales, in which the main vibrating section of the string is augmented by a much smaller vibration in the two ends of the string which are fastened in place.Steinway was a friend of the German physicist Hermann von Helmholtz, and this friendship led to the development and Steinway patent in 1872 of front and back aliquots, allowing the traditionally dead sections of strings to vibrate in sympathy with the main string.