在空弦上演奏双音
Playing on Two Open Strings (Double – stops)

换弦 String Change

练习换弦，最重要的就是在演奏换弦之前的那个音符时，要通过使用整个手臂的动作，把弓毛逐渐地靠近新的琴弦，这样换弦动作就不会生硬了。

When practising string changes, emphasis should be placed on preparing the entire bow arm to go on the new string just before the string change. This allows the bow hair to be closer to the new string, thus minimising abrupt arm movement.

双音 Double-stops

演奏双音的一个重要要求就是把手臂的重量均匀地放在两根琴弦上，这就要靠右手臂的正确平面，而不是靠压力。这对提高控制运弓能力是非常有利的。

The basic requirement in playing on two open strings simultaneously is to put the arm weight evenly on both strings. It requires the right arm to find a suitable arm level for both strings, rather than using pressure. Playing on two strings (double-stops) is useful in raising the student's awareness of the bow arm level on the strings.