Badfinger's "No Matter What"

I'm listening to Badfinger's No Dice, which includes "No Matter What."  I've always like the backing vocals during the later repetitions of "break down the old gray wall" - the ones after the slide guitar part, where the backing vocals are just "ah"s.  Listening to them this time, I decided to figure out the notes, to see why I like them so much.  I was delighted to find that it's a chromatic phrase, from E to B (E D# D C# C B).