Cursory research on this led me to surprise and disappointment. Surprise – mild surprise – that Tony Orlando was American, as this seems to fit right in with same-era UK pop like “Yellow River” and “Love Grows”. And disappointment, having only really taken the chorus in before, that Tony lives above the girl.
Why does that make a difference? Well, I’d assumed he lived below, and so it was his ceiling she was knocking on. Which would have made her ‘knocks’ entirely involuntarily – just walking across the floor might have been enough. (I’m assuming she has a hardwood floor, OK?) Which would have made Tony O a creepy stalker rather than just a lovelorn sap. Which would have made for a somewhat more interesting song.
I’m clutching at straws, because there’s not a lot that’s exciting about “Knock Three Times”. The castanets and faint latinisms of the arrangement are nice, and of course it’s a catchy song, but Orlando oversings it, and his florid smarminess kills off any sympathy I’d feel for his character in the song, too.