With future perfect (F2) you jump to a point in the future, turn round and say some action is finished then. Actually a complicated thing and cumbersome and in most cases you can express the same idea much simpler without using F2. This tense existed in Latin and it was imitated by writers.
In current English usage, muse can refer in general to a person who inspires an artist, writer, or musician.
As a verb, to muse is to consider something thoughtfully. As a noun, it means a person â especially a woman â who is a source of artistic inspiration. In mythology, the Muses were nine goddesses who symbolized the arts and sciences. Today, a muse is a person who serves as an artist's inspiration. Often filmmakers talk about a certain actor being a muse â meaning the actor inspired a movie.