Topmusicanswers
At first glance, this notation looks like too many beats are in each measure, but the three diagonal lines between the notes signal you that this is a tremolo. These two notes share the note length. Therefore, you only count the beats of the first note.
What are the lines on a piano sheet?
A staff is a set of five lines and four spaces on which notes are written to indicate their pitch. The Treble Clef is the top set of lines, the staff, in a piece of sheet music. It shows you the notes to play with your right hand.
What do the lines on music notes mean?
Staff/Stave
Each line or space indicates the pitch belonging to a note with a letter name: A, B, C, D, E, F, G. Moving vertically upwards, the letter names proceed alphabetically with the alternating lines and spaces, and represent ascending pitches.
