With a few exceptions, demos are genial curiosities, adding context but little else to the standard version. You don't hear the song any different after. This one is an exception. Like a lot of folks, I've always found this song from Walls and Bridges particularly haunting, given where John Lennon was in his life (and vis a vis the music business); but this version really got me—the break at 3:36 is just amazing. Go listen. (h/t to Stephen Kroninger) (Stray thought: it might be fun to compile a list of truly essential demos, ones like “I'm Looking Through You." Put 'em in [...]

If you don't know the blog Dangerous Minds, go take a look. I find it essential reading, and check it nearly every day. This morning they posted a YouTube video which lovingly traces the evolution of Strawberry Fields Forever, which I've embedded below. You'll doubtless recognize the tracks (from It's Not Too Bad, Anthology and other places), but it's a nice piece of work, a good use of the form, and well worth listening to. http://youtu.be/QS6wswlJCB4