Symbol sounds

Hello people of the internet,
I am trying to recreate the song Argentum written by Randall B. Standridge.
https://www.jwpepper.com/Argentum/10541812.item#/
My problem is the symbol at the very beginning.
Its a long symbol, lasting 7 beats.
You can find sheet music here also, as long as you don't abuse it.
https://www.jwpepper.com/Argentum/10541812.item#/
Do any of you guys know how to make that really soft symbol.
-MrRoyalSpade
P.S. When I finish this song, I wont post it. I'm doing this song because its a fun exercise.
Copyright wont be an issue :D.