What does the term "rubato" refer to in music?

The term "rubato" refers to the practice of temporarily disregarding strict tempo in music to enhance expressiveness. When musicians use rubato, they may stretch certain notes or phrases, allowing for a flexible approach to timing that can convey a range of emotions. This nuanced manipulation of rhythm creates a more personal and emotional interpretation of the piece, which is especially important in expressive genres like Romantic music.

In contrast, the other options describe different approaches to tempo. Strict adherence to tempo indicates a steady, unchanging pace throughout the music, while a gradual acceleration of tempo suggests a consistent increase in speed without the flexibility that rubato allows. A sudden stop in tempo introduces an abrupt halt, which does not align with the essence of rubato, where the focus is on fluidity and expressiveness rather than on rigid timing.