Question

What does a vertical line to the left of multiple staves indicate to a musician ? A. To play music on all staves at the same time . B. To play music in ascending order of staves, from top to bottom. C. To play music in a descending order of staves from bottom to top. D. Not to play music on these staves.

Answer 1

The answer is A, to play music on all staves linked by the line at the same timw

Answer 2

A vertical line to the left of multiple staves indicate to a musician  to play music on all staves at the same time.