There are little enunciation tricks vocalists use to make sung syllables more understandable, like pronouncing a long I as "aaa-eee." But I heard one today, on the Platters' "Only You (and You Alone)," that I never noticed before: The lead singer, Tony Williams, actually sings, "Only you/Can-d make this world seem right." Or maybe it's "Only you/Can d'make this world seem right." There's a distinct D tucked between "can" and "make" each of the four times Williams sings it.
I had never noticed that before. But once you know it's there, it's hard to hear anything else.