Thanks. That’s still rather confusing, but it’s not your fault ;-). Things like there being 200 people “at the event” (the shooting?). Is that 200 people in the parade? 200 people watching? 200 between paraders and spectators?
We don’t have a Mother’s Day parade here: there will be a big one on Memorial Day.
The band has between ten and twenty people. The spectators are not passively watching the parade - they are following alongside the parade, as an adjacent march.