主音自然音阶的第一个音阶；主音阶。

The first note of a diatonic scale; the keynote.

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“从近几年的历史看，麦田怪圈都与自然音阶（钢琴的白键音符）存在者联系，”她说。 “这些自然音阶出现的频率被编入了怪圈的每个分割区域，可以同钢琴演奏出这些音调。

These diatonic scale frequencies are encoded in each segment of the crop circle and can be played on the piano.

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所增加的七音在主音和下属音三和弦的情况下成为大七和弦，在自然大音阶的其他音的情况下成为小七和弦。

The seventh so added will be a major seventh in the case of triads on the tonic and subdominant, and a minor seventh in the case of other degrees of the diatonic major scale.

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