n.單聲圣歌；素歌

The shape of noteheads has differed historically, as in plainchant. 符頭的形狀在歷史上有很多種，比如在單音歌頌中。

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. 符頭可以是黑色的（圓形或卵形）或白色的，用在五線譜上以表明音高。符頭的形狀在歷史上有很多種，比如在單音歌頌中。