Rubato in Chopin's Nocturne Op. 9 N. 1
Rubato means managing the rhythm flexibility, therefore varying the duration of the written notes.
Used as a concept of flexibility and elasticity of tempo it naturally becomes an instrument of expression.
Being the consequence of a feeling, it expresses a state of mind which becomes more definite in its expression.
For this reason rubato cannot always be done, and it cannot always be done the same way.
No pianist begins Chopin's Nocturne Op. 9 …