After Slay gave a key to Paul McCartney before his concert at Busch Stadium last year, McCartney held the key, bopped around with it a bit, and sing-songed, “I’ve got a key to the city, I’ve got a key to the city.” Slay, a huge McCartney fan, was thrilled.

The tradition of giving keys to the city goes back to medieval times, when cities actually had guarded gates. Only the most trusted of visitors could enter and leave at will. And while the St. Louis keys don’t actually open anything (if Slay is aware of any doors, he’s not saying, though he does own a used, rectangular window from the Arch, the city’s gateway to the west) the symbolism isn’t lost on him.

He hasn’t kept track of how many keys he’s given out, but he does reserve them for special occasions. Among Slay’s recipients: civil rights attorney Frankie Muse Freeman, rapper Nelly, World Series MVP David Freese, Irish ambassador Kevin O’Malley and businessman and former New York City Mayor Michael Bloomberg. The recipient is usually someone who has done something great for St. Louis, and someone Slay connects with personally. “You can’t just give them out willy-nilly,” he said.

And yes, he confirms, people ask for keys. But that’s something he gets to decide.