I have developed a new method for acoustic tuning to improve the harmony of Equal Temperament. The research is based on just intervals and it is still theoretical. The kernel of my theory is the stack of just interval 7 perfect fifths (7 * 3/2) and 1 major third (5/4). The result is perfect fourth and it's ratio (1.3348388671875) is close more than enough the Equal Temperament. The mathematical pby andonoff - Music Theory Questions and Answers