Brackets and braces
Brackets and braces are thick straight and curved lines in the left-hand margin that show instrument groupings.
Brackets
A bracket is a thick black line, the width of a beam, that groups staves together, most commonly according to instrument family. It often has winged ends that point inwards towards the score.
It is always positioned directly to the left of a systemic barline. If secondary brackets are used in addition to a bracket, they are positioned further away from the start of the system to allow space for the bracket.
In Dorico, barlines join the same staves that are joined by brackets and braces, meaning that a bracketed group of staves or a braced pair of staves appears with barlines extending across the group.
Braces
A brace is a wavy or curly line that joins multiple staves belonging to the same instrument, such as the piano or harp. If necessary, a brace can extend to three or more staves, although two is most common.
The brace is also sometimes used instead of a sub-bracket to show groupings of identical instruments within a family whose staves are joined by a bracket.
It is positioned outside the systemic barline, and if used in place of a sub-bracket, outside of the bracket as well.