Vinyl flaw? Problem with system? Rare pressing?

Recently I've experienced an interesting phenomenon with my analog rig. I just got a hand-me-down copy of the Beatles' "Sgt. Pepper..." and on one song (When I'm Sixty-Four) there are absolutely no vocals! Every other song is great. Every other record is great. It's not just a channel missing, it's not just a frequency band missing (the instruments in the song sound great). Any thoughts where my problem may lie? Or do I have an ultra-rare pressing that they forgot to mix in the vocal track of one song? Anyone ever experienced something similar?