The appearance type controls general graphical settings for the music's final form appearance on a printed page of display. This includes support for line widths, definitions for note sizes, and standard distances between notation elements, plus an extension element for other aspects of appearance.
The
<appearance>element.The appearance type controls general graphical settings for the music's final form appearance on a printed page of display. This includes support for line widths, definitions for note sizes, and standard distances between notation elements, plus an extension element for other aspects of appearance.
See
https://www.w3.org/2021/06/musicxml40/musicxml-reference/elements/appearance/