Call me a solipsist! But the only part of the past that is of any importance--or even "exists"--is the past we remember; I am thinking of the largest sense of "we."
This is, of course, the Orwellian purpose for Newspeak, and especially, the memory hole. But it is true, nevertheless.
When our parents die, a portion of our life dies with them--all the history of our childhood they never told us, or of their lives never shared.
When great philosophers, scientists, historians, poets, artists, writers die, not only do their memories of the past die, but whole vistas of the future go with them.
And when we die, the universe ends.
I am greatly saddened when I discover my students know so very little of the things I have valued in my life--not all of which is due to their youth; it is all the more poignant when they are adults. Part of what I feel my vocation to be is to share something of what I value, even if much of it is not entirely connected with music.
The "future" does not exist, I would say, the future does not "exist"--not yet, and not until we have imagined it; and neither does the past.