The younger Mr. Waas was a sheet metal worker at the Philadelphia Navy Yard before enlisting in the Army Air Forces after the United States entered World War II. He served as a pilot in the Pacific Theater.

Image Les Waas in 2004. Credit... via Broadcast Pioneers

In the 1950s, with no experience beyond great linguistic facility and constitutional waggishness, Mr. Waas established his own advertising agency, Waas Inc., in Philadelphia.

In nearly a thousand jingles, he celebrated the virtues of clients including Holiday Inn, the Philadelphia Phillies and at least one local food manufacturer. (“Give me a little Kissling’s Sauerkraut,/It’s fresh and clean, without a doubt./In transparent Pliofilm bags it’s sold,/Kissling’s Sauerkraut, hot or cold.”)

But none captured the public — and held it captive — like the Mister Softee song, which the Oxford Handbook of Mobile Music Studies, Volume 2 (2014), calls “today’s best-known ice cream truck tune,” and of which Mr. Waas remained proud to the end of his life.

The music has been featured on an episode of “Curb Your Enthusiasm,” in which the very sound of it triggers a traumatic flashback for Larry David, and in the 2004 Bernie Mac film “Mr. 3000.” It was recorded by the thrash-metal band Nuclear Assault and inspired the composer Jed Distler’s String Quartet No. 1: “The Mister Softee Variations.”

Perhaps most famously, Mayor Michael R. Bloomberg, in an attempt to rid the city of noise, tried to ban the song outright in 2004 — a sacrilege, akin to banning Frank Sinatra’s recording of “New York, New York,” that elicited howls of protest from the jingle’s adherents.