They are the names that stamped the Indianapolis 500 as a four-wheeled slice of Americana from the heartland. Rick Mears. A.J. Foyt. The Andrettis. Helio Castroneves.

Oh, and don't forget Mrs. Brady and Gomer Pyle.

From Brady to brickyard, from Mayberry to motorsports, Florence Henderson and Jim Nabors provided the soundtrack for the Indianapolis 500 for decades.

The rich baritone voice of Nabors, whose bumbling Gomer Pyle character on "The Andy Griffith Show" has endeared him to comedy fans for decades, anchored his rendition of "Back Home Again in Indiana" that would become a familiar staple of the pre-race pageantry.

"The Brady Bunch" mom Henderson would belt out a patriotic song that reminded fans that Carol Brady could do more than raise her six kids in syndicated perpetuity.

"I think that's part of the success of the race, is that there's a sense of tradition about it," Henderson said.

Citing health reasons, Nabors retired from Indianapolis 500 duties in 2014 after more than four decades. Henderson will skip "God Bless America" as the Indy 500 celebrates its centennial race this weekend. She instead will serve as grand marshal and deliver the "drivers to your cars" command.

And who would say no to Mrs. Brady?

While sports' biggest events generally aim for a new A-list anthem singer or this year's hottest act for a halftime show, the Indy 500 remained loyal to Nabors and Henderson through decades of cultural shifts. When Nabors considered adding "Back Home Again in Indiana" to his touring concert set list, Indianapolis Motor Speedway matriarch Mari Hulman George balked — it was a no-go for Gomer.

"She said, 'Oh no, you only sing it here,'" Nabors said, laughing. "She was very possessive of me."

Nabors attended his first Indy 500 on a lark thanks to a friendship with casino magnate and race fan Bill Harrah. Harrah invited Nabors as his guest to the 1972 race and a chance meeting near the row of bricks with track owner Tony Hulman would lead to the question, do you want to sing a song?

What happened next was the kind of comic confusion that seemed like it was pulled straight from the "The Andy Griffith Show."

Nabors naturally assumed the song was "The Star-Spangled Banner."

"(Hulman) introduced me to the head of the Purdue band. I said, 'What key do you guys do this in?' Well, they said, 'We've only got one key.' No, The Star-Spangled Banner has got two keys. He said, 'You're not singing that.' This is 5 minutes before race time. I said, 'What the hell am I singing?'"

He was singing the song as connected to Indiana as much as Bobby Knight and basketball.

Nabors knew the tune and quickly scribbled the lyrics on his hand. He would sing "Back Home Again in Indiana" almost every year from 1972 to 2014.

"I used to brag to some of my friends. They'd tell me how many fans they had at their concerts," Nabors said. "I'd say, 'Oh, I had about 300,000.'"

According to lore, a band began playing "Back Home Again in Indiana" in 1919 to honor their favorite son late in the race. The tune would become a part of the Indy 500 pre-race pageantry. In 2007, fans sang "Back Home Again in Indiana" when Nabors missed the race because of illness.

The Associated Press interviewed the 27 living race winners on topics ranging from the greatest driver to the most memorable moment. While the winner's milk won with 13 votes, seven chose the singing of "Back Home Again in Indiana."

"It was always my favorite part of pre-race," three-time winner Dario Franchitti said. "I wish they would have recorded Jim singing and continued to use it. I can neither confirm nor deny that I used to sing along whilst sitting in my car."

Indianapolis native Josh Kaufman, winner of the sixth season of "The Voice," will perform the song this year with accompaniment by the Indianapolis Children's Choir.

The 82-year-old Henderson, an Indiana native, tagged along with Nabors one year to the Indy 500 and soon was tapped to sing "The Star-Spangled Banner," ''God Bless America" or "America the Beautiful" 23 times from 1991 to 2015.

"When you're singing and look at that grandstand and you look down and you see all these soldiers, young men and women, it's just very emotional for me," she said.

Henderson has become a huge fan — she has a fondness for fellow "Dancing With The Stars" competitor Castroneves — and stays at the track for the race.

"I watch every minute of it," she said. "I always stay for the entire race. I think I'm the only (celebrity) that stays for the victory dinner. I feel like such a part of the race. As long as they ask me back, I'll be there."