Non-traditional key signatures are represented using a list of altered tones. The key-accidental element indicates the accidental to be displayed in the key signature, represented in the same manner as the accidental element. It is used for disambiguating microtonal accidentals.
The
<key-accidental>element.Non-traditional key signatures are represented using a list of altered tones. The key-accidental element indicates the accidental to be displayed in the key signature, represented in the same manner as the accidental element. It is used for disambiguating microtonal accidentals.
See
https://www.w3.org/2021/06/musicxml40/musicxml-reference/elements/key-accidental/