The metronome-relation element describes the relationship symbol that goes between the two sets of metronome-note elements. The currently allowed value is equals, but this may expand in future versions. If the element is empty, the equals value is used.
The
<metronome-relation>element.The metronome-relation element describes the relationship symbol that goes between the two sets of metronome-note elements. The currently allowed value is equals, but this may expand in future versions. If the element is empty, the equals value is used.
See
https://www.w3.org/2021/06/musicxml40/musicxml-reference/elements/metronome-relation/