I'm not certain if Russia has it's own unique music. (and no just Russia really but eastren europe and the Danes.) Have unique music. I think they do but I can't be certain.

Anyways I love the music, France, England, Germany, the Mediteranian nations, Islamic factions, and Eastren europe factions have excellent music!

I like it it adds depth. I love the losing music to.. lol. Russia hears it alot for me against thosse dreadfull Mongols. It makes thosse last stands more memorable to. I can still remember everything about when Mikhail died defending Iasi.. or Issac in my Byzantines campaign that died traveling with the cavalry that never met up with the main army. I almost always have a Islamic faction campaign going to cause I find the music strangely relaxing. Every faction has music that just fits them. France seems more french with it. Makes me go and fight for French glory. lol. I just like it. Excellent soundtrack, like you'd expect from a TW game.