Double barline
A double barline marks a structural boundary such as a new section, key, metre or tempo. Continue into the next bar unless another sign also instructs a stop or repeat.
- Barlines and repeats
- At the barline
- A straight line
Do not confuse it with
Both strokes are thin; a final barline has a thin stroke followed by a thick one.
What the sources say
- Dorico SE — Types of barlines
It is often used to denote significant changes in the music, or to mark the placement of rehearsal marks, key signature changes, and tempo changes.
- LilyPond Notation Reference — Bars
Various single and double bar lines are available for manual insertion
- Steps to Music Theory — The Basics I
The double bar line is used when the next measure is unrelated to the previous one, when there are specific changes between measures, or when a new section begins.