An octave spans eight notes in a standard musical scale. The pianist played a scale up one octave.
Pro Tip 2/3
Pitch Shift
Shifting an octave changes a note's pitch, but maintains its position in the scale. She sang the same melody an octave higher.
Pro Tip 3/3
Cultural Recognition
Octaves are fundamental in music across different cultures, recognized by listeners universally. Even in different musical traditions, the octave is a familiar concept.