Kellin was with the New Orleans Ragtime Orchestra for the initial festival at Congo Square, a grassy park in the city's Treme neighborhood.
"I miss the early days," Kellin said. "I miss all the local talent, emphasizing local people, regional people."
The first Jazz Fest had four stages for gospel, jazz, and Cajun and zydeco performers. There was an open tent with an upright piano on the grass where gospel groups took turns singing, said festival producer Quint Davis.
Mahalia Jackson, Duke Ellington, Pete Fountain, Al Hirt, Clifton Chenier, Fats Domino and The Meters were among the inaugural performers.
Now, 45 years later, Jazz Fest opens Friday with 12 stages where more than 500 acts and 5,000 individual performers will entertain over the course of two weekends: Friday through Sunday and May 1-4.
Besides local acts like Kellin, who now performs with his own band, the festival card has big names including Carlos Santana, Christina Aguilera, Bruce Springsteen, Eric Clapton, Chaka Khan, Al Jarreau and Public Enemy.
"There's a lot of local music still on display, a lot of jazz, a lot of gospel. It's still something that couldn't happen in any other city," Kellin said.
It's also a benchmark of New Orleans' tourism-based economy.
Mark Romig, spokesman for the New Orleans Tourism Marketing Corp., said hotel occupancy will be near capacity.
This weekend, with Jazz Fest overlapping the Zurich Classic golf tournament and an orthodontics convention, hotel occupancy is projected at nearly 99 percent. The second weekend, occupancy is expected to be around 95 percent. Industry officials said there are more than 36,000 hotel rooms in the area.
Romig said Jazz Fest attracts national and international fans — more than 100,000 are expected — in addition to hundreds of thousands from around the region.
Riding around the Fair Grounds Race Course, where the festival moved in 1972, Davis said he's in awe of the festival's growth. In 1970, there were fewer than 400 attendees. One of the organizers went to a nearby school and asked if the students could take a field trip to the festival to boost attendance, he recalled. Last year's festival drew 425,000 people.
"Here we are 45 festivals later and it's pretty amazing, when you think about all the changes that have happened in that time with society, the economy," Davis said. "Our advantage is the culture of New Orleans, because the culture of New Orleans is not a fad."
Three stages are tied to New Orleans jazz and Louisiana culture, with at least 27 brass bands, many Mardi Gras Indian troupes and more than 50 gospel groups with roughly 2,000 singers.
The festival has set its lineup to complement big-name global talent with local performers, Davis said.
So sharing the stage with Irma Thomas and Tab Benoit will be Eric Clapton. The Radiators will play before John Fogerty, and Marc Broussard and singer-pianist Allen Toussaint will perform before Bruce Springsteen and his E Street band.
"It's the same palate, musically, that we had that first year in Congo Square," Davis said. "There's more of it, but it's rhythm and blues. It's gospel. It's second-lines. It's everything that we started with, just really grown up."