Seeking a definition

Pitch is determined by a sound’s frequency. Notes that sit in different positions on a musical scale, called tones, have different pitches. Modern Western music, for example, combines 12 tones, with the A at the middle of a piano keyboard having a frequency of 440 hertz. Other cultures work with fewer tones. The first few notes of “Twinkle, Twinkle, Little Star” vary only in pitch.