an arrangement as illustrated in fig7 the positional constant string pitch control system 14 or 30 can be employed in combination with a bridge 27 the positional constant string pitch control system 14 or 30 can be mounted to the soundboard 26 or independent of the soundboard 26 for employment as an intonation point an adjustably tensioned spring 18 or arrangement of springs 18 can be combined with the pivot structure 10 or the bearing 8 or the mounting structure 15 to counteract longitudinal string 5 tension force on the rotatable surface 1 or the positional string pitch control system 14 or 30 as illustrated in fig6 7 and 8 the spring 8 or arrangement of springs can be self contained within the positional constant string pitch control system 30 as illustrated in fig6 or configured between the instrument and tremolo input device 22 as illustrated in fig1 or configured between the positional constant string pitch control system 14 or 30 and the instrument as illustrated in fig8 the tremolo input device 22 can be positioned above even with or below u2014 as illustrated in fig7 u2014 relative to the plane of the string 5 the relationship between the spring 8 or springs and the positional constant string pitch control system 14 or 30 and the instrument can employ a combination.