As you read or write piano music, reading and writing ledger lines for more than four or five notes above or below the grand staff can get a little ridiculous. After all, if you were to keep using ledger lines, you’d take up an impractical amount of space, and reading all those lines would become tedious not to mention confusing.
That’s why composers invented the octave, or ottava line, which tells you to play the indicated note or notes an octave higher or lower than written. The abbreviation 8va means play an octave above, and 8vb means play an octave below:
