I wouldn't use the word dark to describe anything George did (and consider: Beware Of Darkness), though it's certainly there in some of John's stuff - '...just had to laugh...' Tomorrow Never Knows I think was intended to be genuinely spiritual, but the music seems kind of dark. Some of the music in George's songs might seem dark, but I think George never intended it to sound that way. Except that the darkness of the music in Blue Jay Way might have been intended to act as a warning - 'Please don't be long.' I know it was based on friends who couldn't find their way to his home, but, I wonder if it's a hidden spiritual reference. Like I suggested with Savoy Truffle.