What does 'rallentando' mean in the context of tempo?

'Rallentando' is an Italian musical term that indicates a gradual decrease in tempo. When a musician sees 'rallentando' in a score, they should slow down the pace of the music progressively. This effect can create a sense of tension, emotional weight, or anticipation, providing a dramatic shift in the piece.

The other choices do not accurately define 'rallentando.' For instance, 'con fuoco' translates to playing 'with fire,' which conveys an emotional intensity rather than a change in speed. Similarly, 'quickly' suggests an acceleration, contrasting with the slowing nature of 'rallentando,' and 'heavily' implies a weightiness rather than a specific tempo adjustment.