Dear musicians,

I really need some help figuring out how to get the music sheet for this piece. It is from an old anime called Giant Robo soundtrack. The title listed is "String Quartet - The Great Dusk" by Masamichi Amano. It is a beautiful piece and I would like to have it played at my upcoming wedding. I searched and searched, but no luck finding the music notes for it (i searched the title of the piece and the artist). However I think this is actually a classical piece and they just remixed it because it does sound familiar. I am no expert so I came here hoping to get some help.

please listen to it at this link:

thank you sooooooo much!