Which term describes a musical style characterized by a grand and grandiose expression?

The term that describes a musical style characterized by a grand and grandiose expression is "Grandioso." In musical terminology, "Grandioso" is used to indicate a style that is expansive, majestic, and often with a sense of grandeur in its performance. This is typically reflected in rich orchestrations, powerful dynamics, and an overall sense of boldness that aims to convey strong emotional content.

In contrast, the other options relate to different aspects of musical expression. For instance, "Giocoso" suggests a playful and cheerful style. "Legato" refers to a smooth and connected manner of playing notes, emphasizing continuity without breaks. "Largo" indicates a slow tempo, focusing on the pacing of the music rather than its grandiosity. Each of these terms signifies important musical concepts but does not capture the essence of grand expression as effectively as "Grandioso."