Two decades go by in the blink of an eye. It seems like last week that the city welcomed a boyish, floppy-haired moppet as the 20th conductor of the Boston Pops. This season, which begins on May 6, marks Keith Lockhart’s 20th anniversary with the orchestra. “It’s impossible to believe,” he says. “I always knew it was a long-term commitment—but wow.”

Before taking up the baton in Boston, Lockhart was the associate conductor of the Cincinnati Symphony and the Cincinnati Pops. When he arrived here, he had large shoes to fill. “The job had only been up for grabs once before since 1930, so the odds were slim I’d get it,” he says. “But after a two-year courtship, all of a sudden, I’m sitting at a press conference between John Williams and Seiji Ozawa, with all these flashes going off, and I thought, take a deep breath.”

Now, 1,671 concerts later, he’s shared the stage with a staggering list of luminaries. A mere sampling: Aerosmith, Ben Affleck, Buzz Aldrin, Jason Alexander, Big Bird, Mariah Carey, Harry Connick Jr., Elvis Costello, Sir Elton John, Toby Keith, Nathan Lane, Yo-Yo Ma, Shaquille O’Neal, Steve Martin, Jessye Norman, James Taylor, Sting, Bill Clinton, Ted Kennedy and Elizabeth Warren. He’s also led 40 national and four international tours. “It’s an awesome responsibility,” he says. “It really is America’s Orchestra. I hope to keep the Pops as a relevant entertainment option and honor that 130-year legacy of playing great music for people who don’t know they like it until they hear it.”

So how does it feel to be the Pops’ second-longest serving maestro (after legend Arthur Fiedler, who served from 1930 to 1979)? “I still feel like I’ve got something to offer, but I can’t imagine that it could ever be good for either me or the institution to have a 50-year relationship.” Oh, well. Here’s hoping for at least 20 more.To that end, he’s overseen numerous firsts during his tenure. In 1999, the orchestra garnered its first Grammy nomination. In 2005, it launched EdgeFest, which pairs the Pops with indie musical acts. Last year marked the first webcast of the July 4 fireworks and concert on the Esplanade, streamed live worldwide. This season debuts another innovation: By Popular Demand concerts (May 7, 16, 26, 29 & June 5), where audience members can vote in real time for what they want the orchestra to play. “So much of our world has become on demand or available online,” Lockhart says. “I think one of the things the Pops has to offer is the concept of community, a shared experience, being part of a live audience.”