由于全音阶相邻两音等距离的音级结构，使其失去传统调式的纯四、五度音程与小二度音程，从而完全没有大小调体系中的重要特点。
As the equidistant structure of degree in adjacent notes of diatonic scale , made it loses the 4th or 5th interval and minor second of traditional mode , so that there is not enough important features of tonality system .
纯四度