"double bar" 的定义和意义

What is a "double bar"?

A double bar is a musical symbol consisting of two vertical lines placed close together on the staff. It is used to indicate the end of a section or movement within a piece of music. Double bars help to divide the music into distinct parts, making it easier for musicians to navigate and understand the structure of the composition. They also signal changes in the music, such as a shift in key, tempo, or a new section.