The song "Butterfly Flying" is in four-three beats and four-two beats. The beautiful and lyrical melody is written in 4/3 time and the lively and cheerful theme melody is written in 4/2 time. Beats in music. In music, time is divided into equal basic units, each unit is called a beat or beat. The law of strength and weakness is: strong---weak---weak. 4/3 means four-three beats. Four-three beats are a kind of beat. Each measure has three beats with a quarter note as one beat. The duration of each beat is determined by the speed of the music.