I've spent several days looking for music that sounds like "Time I" by the metal band Wintersun before the metal happens, to no avail. I can't seem to find the right thing to google, and looking up "music that sounds like the beginning of Time I by Wintersun" or anything of that sort doesn't yield good results either. "Ambient symphonic music" was the best thing I could think of to look up, but industrial neofolk and philip glass were basically all I was getting.
I can't watch the video here, but i'm assuming you've sent this music.
It's definitely the style of epic medieval soundtracks. It draws inspiration from medieval music but i would not describe it as folk. You're up to find what you're looking for in the soundtrack area, especially for movies, but eventually for games. Shadow of the Colossu's OST deserves your attention. Also try The Elder Scrolls V: Skyrim. Oh, and i couldn't not mention Lord of the Rings.
Be aware though that soundtracks are long and heterogenous, so it will take you some time to find the right tracks.
While some cinematic stuff can focus on a more modern approach, on this one you can feel a bit more of medieval stuff (while, of course, it's still only an 'flavor')
A lot of metal bands draws from medieval stuff folk songs, like celtic/irish/nordic/etc and mix with symphonic and cinematic styles, so you can also take a bet on other similar metal bands. In this place i can't help you much, but it's a direction.
Also there are some people actually making 'stand-alone albums' inspired by that kind of music, but i don't know many names.
My best guess would be to call this "epic new age" music. I did a search for that on YouTube, and this is the first thing that came up:
To my ear, at least, it's in the same general ballpark.
A few songs that might be interesting -
- Eluveitie - Isara
- Eluveitie - The Liminal Passage
- Eluveitie - Inis Mona (Instrumental)
- Ash - Mosaique
- Zariya - AR Rahman
- Wintersun - When Time Fades Away
- Kamelot- A Sailorman's Hymn
- Snuff - Slipknot
- Apocalyptica- Faraway
An exhaustive discussion could be found at https://www.escapistmagazine.com/forums/read/18.231245-Unexpectedly-good-slow-songs-from-heavy-bands