Rubato involves subtly speeding up and slowing down the tempo during a phrase or passage and is usually achieved by holding some notes slightly longer than written and shortening others.
Rubato is a musical term meaning "robbed time which refers to a technique in which a performer slightly alters the tempo of a piece to create a more expressive and nuanced interpretation.
Rubato allows pianists to shape individual phrases and emphasize specific notes or melodic lines. This can create a sense of naturalness and flow in the music. The careful use of rubato can convey a wide range of emotions, from tenderness and sorrow to joy and excitement and can also highlight the dramatic tension and release within a piece.
Rubato adds a human touch to the performance, making it feel more spontaneous and expressive than a purely metronomic interpretation.