This song is the background music of Wings of Liberty, and the sound is very beautiful. Unfortunately, this song is not included in the official soundtrack CD released by Blizzard, so the name is unknown. If you want, you can only extract it from the game. It is the ogg version, and the effect will only be better than ordinary MP3. There are two versions of this music. The beta version of Wings of Freedom is different from the official version. A lot has been cut out of the official version, so I still feel that the beta version sounds better. If you need it, I have the official beta version in Ogg format and can send it to you for comparison.
PS: The URL you sent is the beta version of music.