Rhythm/ˈrɪðəm/ Definition 1 of 5Pro Tip 1/2Musical Foundation In music, 'rhythm' is fundamental, often driving the speed and feel of a piece. A strong rhythm is essential for a catchy tune. Pro Tip 2/2Expressive Movement 'Rhythm' influences how people react and move to music, whether clapping or dancing. The crowd clapped in rhythm during the concert.