You may be among the legions who have sung along with the “Wings” 1971 hit, “Uncle Albert/Admiral Halsey.”

“Admiral Halsey notified me.  He had to have a berth or he couldn’t get to sea.  I had another look and I had a cup of tea and a butter pie.
Butter pie?  The butter wouldn’t melt so I put it in the pie.”

Well, after 50-years, someone’s asked Sir Paul McCartney, what exactly is a “butter pie?”

It turns out, you don’t know and neither does he.

In an interview on PaulMcCartney.com, he admits he just made it up, explaining that he was into surrealism at the time and so was former Beatles band mate John Lennon, which Sir Paul says was one of the things they bonded over.