I've been listening to this song all day long for quite a while now and I'm convinced it is perhaps one of my favorite songs ever.
It's called A Change of Seasons
by the progressive metal band Dream Theater. Don't let the length of the song or the "metal" tag dissuade you; it's a brilliantly crafted piece of musicianship and among the best songs the band has ever written.
The song is a 23-minute long epic split into seven parts, three of which are insturmentals:...