sostituendo
Sostituendo is an Italian musical term that translates to "replacing" or "substituting." In musical composition and performance, it refers to the act of replacing one element with another. This can encompass a variety of musical aspects. For instance, a composer might indicate a passage to be played by a different instrument than originally intended, or a performer might choose to substitute a particular note or chord for expressive or technical reasons.
The concept of sostituendo is particularly relevant in the context of improvisation or when dealing with variations