I'm not sure if this should go here or in the D.Gray-man request.

But I've been annoyed at the that there wasn't a sheet music/midi (that I could find) of Snow Kiss by Nirgilis.

And I found a music book that contained it, I went and bought it off Ebay. Just recieved it. It has the piano, singing and chord accompany. And when I tried it out, the melody? on the right was slightly off for the piano at some parts while the singing part was off at certain times.

I was wondering if when people arranged music include the melody of the singing, or just the main tune?

And would it be wrong of me to combine the two (piano+singing parts) and asked someone to check whether the combination was similar to the actual song?