There is already several threads about in-game music. What I want talk about is the out-of-game music, in trailers, promos and so on.
What I remember the most about Dishonored is the theme song. The trailer featuring it set the right atmosphere and made me look forward to the game’s release. Having some touching music be part of the pre release promos of Kingdom Come would be awesome.
As to what the theme song should be like, I’d prefer some contemporary music with English lyrics, maybe with some small hints pointing to the medieval inspiration. I believe that having English lyrics is important for people to really appreciate it and and to make it feel relevant for them. KC:D is after all not some ultra realistic hardcore medieval simulator for just history nerds, but a game that aims to demonstrate that one does not have to sacrifice historical accuracy to deliver an interesting gameplay and story.
Warhorse made this mistake once already. Do you remember the publisher build demo, which consisted of a ton of talking, wandering around in peasant clothes without a weapon and one superlong swordfight that got tedious to watch rather quickly? Showing the publisher the most boring part of the game? And you wonder they put you down? For Kickstarter Warhorse released the cinematic-ish trailer, which put on display much better show. There was large battle and lots of other eyecandy. Moreover, they managed to position themselves among indie games, so compared to the promo other games were able to show, this shined.
Talking about songs, have you people notice the song “My Kingdom Come” recorded by the group Imagine dragons? That name is actually quite funny coincidence. 