What does rinforzando require musicians to do throughout a phrase?

Rinforzando, often abbreviated as "rf," is a musical directive that instructs musicians to increase the volume of a note or a passage, typically executed over a short duration. This dynamic marking adds emphasis and intensity, creating a striking contrast within the music. By increasing the volume, musicians bring attention to the specific moment or phrase, enhancing emotional expression and musical impact.

In contrast, maintaining a constant volume would not fulfill the intent of rinforzando, as it does not involve any dynamic alteration. A gradual decrease in volume is indicative of a decrescendo, which is fundamentally different from the sudden emphasis required by rinforzando. Accentuation of the first note, while it draws attention, is not synonymous with the dynamic swell indicated by rinforzando, which specifically calls for an increase in volume rather than just emphasizing a single note. Therefore, the choice of increasing volume over a short period perfectly aligns with the definition and application of rinforzando in music.