If you want to play keyboard or piano, you will need to have a firm grasp of bar lines. In addition to horizontal staff lines, music employs some vertical lines to help you keep track of where you are in the music, sort of like punctuation in a written sentence.
A bar line divides music into measures or bars, breaking up the musical paragraph into smaller, measurable groups of notes and rests. Measures help organize both the writing and reading of music for the composer and the performer.
Be prepared to see a few other types of bar lines in piano music. They give you directions on how the music is structured, when and where to repeat, and when to stop. Following are the names of the five types of bar lines and details on what they tell you to do:
Single: Go on to the next measure.
Double: Proceed to the next section (because you’ve reached the end of this one).
Start repeat: Repeat back to this measure.
End repeat: Repeat back to the measure that begins with a start repeat (or to the beginning if you don’t see a start repeat).
Final: You’ve reached the end! Stop playing!
