Two all beef patties, special sauce, lettuce, cheese, pickles, onions on a sesame-seed bun.
BUT CHECK IT OUT: these lyrics don’t even mention the defining feature of a Big Mac: that it’s a double-decker burger. There’s a slice of bunstuff between the two patties! That’s really important! THAT’S WHAT MAKES IT A BIG MAC.
The Big Mac Song lyrics are actually describing a different burger! They are describing a mere double cheeseburger. Or, as you might know it:
A Double Whopper With Cheese.
Your argument is that they’re failing to mention the bunstuff in the middle but then you clearly missed the tomato in the middle of the Double Whopper With Cheese.
Please revise your theory before wasting my time any further.
1 - Burger King’s slogan is “Have It Your Way” and one way you can have a Double Whopper Meat Sandwich your way is without tomato. OH SNAP
2 - Also, I’d argue that the Big Mac song is the minimum sufficient standard for a Big Mac: you can get extras put on it if you want, like oh I don’t know TOMATO