The many planned commemorations for the centennial of Frank Sinatra's birth on Dec. 12 have already begun. James Kaplan just published the second and final installment of his biography, Sinatra: The Chairman. Tina Sinatra's book from 2000, My Father's Daughter: A Memoir, has been reissued. Sinatra 100 - An All-Star Grammy Concert will be taped this week in Las Vegas and air Dec. 6. It features Tony Bennett, Garth Brooks, John Legend, and Alicia Keys. And at noon on Sinatra's birthday, HBO will re-air Alex Gibney's two-part documentary Sinatra: All or Nothing at All.

But at the Philadelphia studios of WPHT-AM, Sid Mark doesn't need a milestone to celebrate Sinatra. It's something he has been doing since a listener suggested he play a solid hour of Sinatra 59 years ago. Sid never stopped. And in 1979, a syndicated version of his The Sounds of Sinatra was rolled out across the country, airing on 100 stations from coast to coast.

Sinatra passed in 1998 at age 82. While Sid might be in the autumn of his years, he told me recently that Frank Sinatra Jr. reminded him that his father was in the business 60 years, which Sid took to mean he's not finished yet.

"I admire him like an older brother," Frank Jr. told me last week. "I respect his dedication to doing things in a way he has always done them," he added, noting that his father was eternally grateful that Sid kept the music going for his radio audience all these years.

That gratitude was on full display in front of 17,500 people at a sold-out Sinatra show at the Spectrum on Nov. 9, 1991. Old Blue Eyes interrupted the performance to raise his glass to Sid Mark, who looked on with his family. The two had first met at the Sands in Las Vegas in 1966 after Sinatra invited him to be his guest. In Philadelphia, the tuxedo-clad Sinatra first offered a toast in Italian, and then explained:

"That means 'I wish for you to live to more than 102 years or 204 years. And I'll be around looking at you all the time.' I should like to take a moment to introduce to you a friend who has been a friend for as long as I've been in this business. That's been a long time. This guy is some kind of a man. You all know him so well, because he lives among you here, and I should like to have him stand to take a bow. And I speak of the wonderful Sid Mark and his family, who are here this evening. There he is right there. I drink to you, Sidney.

"It's wonderful to have a friend like Sidney. And I've had maybe four or five in my career of people who have stayed with me when things were dark and didn't change at all whenever anything else changed. And that's the kind of man he is. And I love him, and I say that publicly. I love him. He's one of the best friends I've ever had in my life. I had a lot of friends, but about three days later they were all gone. I ran out of money. But Sidney is a great man, and he's absolutely wonderful."

Jerry Blavat, who was tight with Sinatra and has known Sid since the 1960s, wasn't at the Spectrum that night. But he did see Sinatra, still clad in his tux, later that evening at Jilly's Saloon in Manhattan. "I was at the bar with Frankie Valli, and the place was empty," Blavat said with a laugh. "Fabian was there, too. Well, Frank walked in around midnight and suddenly it was packed."

"Sid's never followed a research chart," Blavat said of his friend and colleague. "Sid knows all there is to know about Sinatra because he loves Sinatra. He eats, breathes, and lives Sinatra."

Joe Piscopo, perhaps best known for his Sinatra impressions on Saturday Night Live between 1980 and 1984, is another fan of both men. Piscopo noted that most who know Sid are listeners who've never had the pleasure of meeting him. But for the lucky ones who do, the best is yet to come.

"Often you hear a person on radio and then meet them and it's a letdown. But with Sid, knowing him is the icing on the cake," Piscopo said.

Today, the former SNL star often headlines casino showrooms doing Sinatra. On the birthday, he'll be singing Sinatra with a full orchestra at the Sands in Bethlehem. But for Sid, he was once willing to play a restaurant in South Philly.

Four years ago, on Sid's 55th anniversary, he asked Piscopo to sing Sinatra at Galdo's, a catering hall on West Moyamensing Avenue. Piscopo had a scheduling conflict with a family wedding.

"My cousin Pauly from Jersey said, 'You have to be at my daughter's wedding,' " Piscopo said. "Then Sid invited me to sing Sinatra. The only way I could make it work was to take a helicopter from one to the other. Only for Sid would I sing Sinatra in a restaurant and then take a helicopter to a wedding. And Sid got the City Rhythm Orchestra to play with me and the night was magical."

Frank Jr. has often sat in Sid's studio, marveling as he applied his trade.

"Sid as a broadcaster is old-fashioned, old-school. He's . . . incensed at the thought of making music on a computer. He now uses CDs, but he's still 'jockeying discs' - most in radio never even heard the expression," Frank Jr. said.

Junior credits Sid's wife, Judy, as Sid's inspiration - she has been the lady who never left her escort.

That night at the Spectrum, after Sinatra toasted Sid Mark, Old Blue Eyes introduced a song by Rodgers and Hart telling the crowd, "We all know of these songs, because I don't do anything that's new, because there's nothing new."

It's the same with Sid.

Michael Smerconish can be heard from 9 a.m. to noon on Sirius XM's POTUS Channel 124 and seen hosting "Smerconish" at 9 a.m. Saturdays on CNN.