Musical notation was conceived for the C major scale and each line and space represents a note in this scale.

乐谱为C大音阶而构思，在这个音阶中的每一个线和间都代表一个音符。

《柯林斯英汉双解大词典》

Let's start with a major scale on a c.

让我们从C开始一个大调音阶。

youdao

Let's start with a major scale on a C.

让我们从C开始一个大调音阶

耶鲁公开课 - 聆听音乐课程节选

Mr. Blake derived a simple melody by playing a few dozen digits of pi using a C-major scale, with 3, 1, 4, 1, 5, 9 translated to the notes E, C, F, C, G, D and so on.

WSJ: We Can All Have a Slice of Pi | Postmodern Times by Eric Felten