This principle ignores that the frequency of a vibrating string is calculated by three factors: the mass of the string, the tension applied and the speaking length. var ratio = 0.5625; Resources { var width = $(window).innerWidth(); Predicted Effects of Intonation Accuracy on Vocal Performance Quality. I used to be a full-time guitar instructor and had taught hundreds of people how to play the guitar. /* */. Have a little patience, and you’ll be one your way to perfect tuning in no time.