The musical term that signifies a gradual volume increase is “Crescendo,” not Allegro, Legato, or Fortissimo. While Allegro refers to a fast tempo, Legato describes a smooth and connected style of playing, and Fortissimo indicates a very loud dynamic level, it is Crescendo that specifically denotes a gradual increase in volume or intensity in music. Musicians use the term Crescendo to indicate that the music should become progressively louder over a specified duration, adding depth and intensity to the performance.
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