将这两种双音放在一起加以论述是因为这两种双音手形都是扩张手形,也可叫非正常四度框架手型。换指八度双音的难点在于音准,所以音准的训练是第一步,方法同于八度双音训练。第一步:先练习1、3指框架纯八度,1指按弦发音 ,3指按弦不发音 ;【谱例1】后练习1、3指框架纯八度,1 The two dual-tone together to be discussed because these two dual-tone hand are expanding hand shape, also can be called non-normal four degrees frame hand. The difficulty of changing octave double refers to pitch, so pitch training is the first step, the same way as octave dual tone training. The first step: first practice 1, 3 refers to the frame pure octave, 1 refers to the string according to the pronunciation, 3 refers to the string according to the pronunciation; [spectrum 1] after the practice 1, 3 refers to the frame pure octave, 1