Best OST (BGM -background music/instrumental- only)

BGM is very powerful: it raises the beauty of a drama, it makes you feel emotions in a deeper level and it transports you in another realm. 

I especially love listening to BGM before sleeping, when studying of just for daydreaming

Sometimes, BGM are not available or I couldn't find them  T o T

Check also my list "Best OST (song only)"