In the 1970’s there was a band called Hamilton, Joe Frank and Reynolds and they had a number of hits including Don’t Pull Your Love and Fallin’ in Love. They were an awesome band but I bet you don’t know what their first single was.
In 1966, (as the T-Bones, a studio band- and before they became a live band) they had a song called No Matter What Shape (Your Stomach’s In). It was an instrumental only and was used in an Alka Seltzer commercial.
Hit this Youtube link to see if you’ve heard it- you may have to scroll down and pick the first one to get the link to work. I bet you have heard it.