The Piano strings are under a great deal of tension that is supported by the frame, plate (Iron Frame) , Pin Block, Tuning Pins, Bridges and Sound Board. Anything that affects the position of these parts will cause a change in tension and make a the piano go out of tune.
Factors that are influenced are as follows :-
• Humidity
• Temperature changes
• Stretching of the strings
• Slipping of tuning pins (common to an old piano)
• Playing (the more you play & even the touch of the player – if the touch is heavy or soft etc;
