Edit 2: Now if I could just figure out why I can't get my musician to play Rambler from Slavs a second time I'll be happy.
First of all I'm not happy I can't hear "Rambler from Slavs" again !
Indeed, I've the same "problem" as DocSmith59 and I've tried it many times already ! Other music tracks I asked to play to Kirill he plays them (I play Xbox), but no 'Rambler from Slavs'

.. sadly, because it's a very nice song/track !
Further on about killing Raze :
I discovered (after many try & error) that a Creature with a Ghooulish Head (Rush Attack & Fatality!) is most usefull help to kill Raze . The last time confronted with Raze I summoned the Undead too and used Thousand Strikes and my Creature make an end on Raze's life by using Fatality. I was at least level 30 . I also use "Charm" on Walking Armors to have the most profit (the more damage "we" can do the faster Raze is killed).
Next time I go for a Warrior Priest build and wish to try killing Raze on nightmare without the help of my creature, so :
"...killing your enemies up close and personal is the most satifying way ... or something like Gawain in Farglow said to me
And in combination with the Priest skills Charm, Blind, Curse, Fear, Summon Ghost, Hide in Shadows, ... and some Warrior skills this playthrough can't be missing his goal for me : having big big FUN !