Memphis is noted mainly for "dry" ribs. Instead of sauce, a dry rub is applied before the ribs are smoked. Not that this isn't done elsewhere but Memphis is associated with dry ribs. Of course, folks always have the options of adding sauce to their ribs.
St Louis refers to a square cut rack of spare ribs...the meatier, longer ribs from the belly.
Kansas City rib joints vary from tangy tomato to sweet tomato sauces. KC Masterpiece is a KC style sauce.
Now I want some ribs