What characteristic does 'legato' typically add to a musical performance?

'Legato' is a musical term that indicates that notes should be played smoothly and connected to one another, without any noticeable breaks or interruptions between them. When a piece is performed legato, the notes flow into each other seamlessly, creating a characteristic of smoothness that enhances the overall expression of the music. This technique allows for a more lyrical and connected sound, which is especially important in expressive melodies.

The other options do not align with the essence of legato. Harshness and strong accents suggest a more detached and forceful playing style, while fast rhythm refers to the speed of the notes rather than their connection. Thus, the defining feature of legato is indeed the smooth transition between notes.