From Playboy mag, Sept. 1987, Jon speaking-

"We made a lot of friends, gave them nicknames. Richie, he calls me Captain Kidd. The king of Swing is Richie's nickname. His comes from two California women whose names have to be protected, but one of them is an L.A. rock star and she saw Richie one night, late. She called him the King of Swing, and I guess I should evade the rest, because he had a lot of fun with them."

There you have it! Wonder who the "LA rock star" could be?