What is the role of a barline in sheet music?

The role of a barline in sheet music is to divide measures. This is crucial for organizing the music into manageable sections that correspond to the time signature, helping musicians understand where each measure begins and ends. By visually separating the measures, barlines provide a clear structure for pacing and counting, allowing singers and instrumentalists to perform in sync.

While breath marks indicate places where a vocalist can take a breath, separating different sections usually involves other markers like double bars or more significant breaks in the music. Similarly, the end of a piece is indicated by a double barline or a final closure marker, rather than a single barline. Thus, the function of a barline is specifically focused on dividing the music into measures for clarity and organization in performance.