There probably won't be any drums all the time in the soundtracks.
Indeed, the game can have a wide variety of different types of music to fit the different moods it would produce, and it's not like we've heard a large amount of music from the game, in fact, I only recall hearing two seperate songs from it, the theme song, and that ambient piece that was played in one of the videos. I hardly think we can say what does or does not fit in with the style of the music in the game based on what we've heard so far.
This track sounds like the sort of thing I could see being in the game, though, but is it really from the game? I don't know, I guess we'll see, if it is, I'm guessing it plays in the wilderness, with the tranquility of it.