Some Russian music fan, insane, completely losing head (10,5)
I believe the answer is:
nutcracker suite
'some russian music' is the definition.
'nutcracker suite' can be an answer for 'music' (I've seen this before). I'm not sure about the 'some russian' bit.
'fan insane completely losing head' is the wordplay.
'fan' becomes 'nut' (I've seen this before).
'insane' becomes 'crackers' ('crackers' can be similar in meaning to 'insane').
'completely losing head' becomes 'uite' (I can't explain this - if you can you should believe this answer much more).
'nut'+'crackers'+'uite'='NUTCRACKER SUITE'
Can you help me to learn more?
(Other definitions for nutcracker suite that I've seen before include "score?" , "music" , "Set of pieces" , "composition" .)