When a ritard is indicated in a musical piece, the performers should gradually reduce the speed of the music until the next tempo indication or the end of the phrase or section. This slowdown should be smooth and controlled, allowing the music to come to a natural conclusion.
Ritard is often used to create a sense of drama or suspense, to bring a piece to a close, or to transition between different sections of music. It is a versatile musical expression that can add depth and emotional impact to a performance.