Tremolo is a rapid, repeated variation in the volume of a musical note that creates a shimmering, wavering sound. When a violinist plays tremolo, they move their bow back and forth across the string incredibly quickly, making the note flutter. When a singer uses tremolo, their voice wavers slightly in loudness, adding emotion and intensity to the sound.

You can hear tremolo in lots of music. Classical composers use it to build tension in dramatic moments: imagine the trembling strings in a suspenseful movie scene. Guitarists create tremolo by rapidly picking the same note over and over. On an electric organ, pressing the tremolo button makes the sound pulse and shimmer.

Some people confuse tremolo with vibrato, but they're different. Vibrato is a smooth, regular wave in pitch, while tremolo is that rapid, fluttering change in volume. Both add expression to music, but tremolo has a more urgent, shimmering quality that can feel especially intense.