What is the opposite of 'rilassato', a tempo marking that indicates slowing down?

The term 'rilassato' in Italian translates to 'relaxed' and typically indicates a more leisurely tempo, suggesting a slowing down in music. The opposite of this concept involves a term that signifies an increase in speed or a quickening of tempo.

The correct answer, which indicates this increase in tempo, is known as 'accelerando.' This term specifically instructs the performer to gradually speed up the tempo of the music, directly countering the effect of 'rilassato.' By using 'accelerando,' the music shifts from a relaxed pace to a faster one, creating a sense of urgency or excitement.

In contrast, the other terms listed — 'presto,' which denotes a very fast tempo, 'ritardando,' which means to gradually slow down, and 'allegro,' which indicates a lively and fast tempo — do not serve as the direct opposite of 'rilassato' in the way 'accelerando' does.