Pythagoras viewed music as a branch of mathematics and discovered relationships between the pitch of notes and string lengths. He developed one of the first mathematical scales based on octave and fifth intervals. Mathematics is involved in many aspects of music including frequency, duration, time signatures, rhythm, intervals, chords, counting, conducting, and contemporary music forms like 12-tone music which are based on mathematical matrices. Fractions represent note values in musical notation and show the relationship between notes and rhythmic movement in music.