User blog comment:Master Sima Yi/Assassinews 14-07-'14 – Two new Assassin's Creed: Unity trailers/@comment-4254431-20140729161813/@comment-13471981-20140731161806

You mean the "Justice for All" one? Could be, I don't know where that song is from. The reveal trailer used "Glass" from Bat for Lashes, but I doubt that's who you're thinking of.