n.单声圣歌；素歌
The shape of noteheads has differed historically, as in plainchant. 符头的形状在历史上有很多种，比如在单音歌颂中。
Noteheads may be black (a circular or oval shape filled in) or white and are used on the staff to indicate pitch. The shape of noteheads has differed historically, as in plainchant. 符头可以是黑色的（圆形或卵形）或白色的，用在五线谱上以表明音高。符头的形状在历史上有很多种，比如在单音歌颂中。
