Measures and Bar Lines

Measures are groupings of notes, usually grouped by meter. Bar Lines show us where one measure ends and another begins.

There are different types of Bar Lines, each with a different function

A Single Bar Line is the normal Bar Line, it tells us where the measures are:

A Double Bar Line shows there is there is a major change in the music, such as a new musical section or new time signature:

A "Final" Double Bar Line shows that the piece of music is over: