But given that the theme of the night was "Countdown to Gold," his training for the London Olympics wasn't far from his mind — although first, he said, he has to get past a talented U.S. field in the qualifying trials that will be held in Omaha in June.
Phelps and his teammates took a break from their intensive training to attend the gala, which raised money for the North Baltimore Aquatic Club in Mount Washington. Based at Meadowbrook pool where the now 26-year-old Phelps first learned to swim, it has a long history of producing Olympic swimmers, several of whom returned to town for the party.
Phelps said he enjoys being around the kids who swim both recreationally and competitively at the pool, and finds himself more relaxed as he trains for his fourth and final Olympics. Much of that, he said, is due to his training partner, Allison Schmitt, a bronze medalist in 2008 who red-shirted her senior year at the University of Georgia to train at the NBAC.
"I like to joke a lot," Schmitt said, prompting Phelps to echo, "A lot."
They are two of the 24 NBAC swimmers who qualified for the U.S. trials.
While Phelps trained in Michigan for the 2008 Beijing Olympics, he returned after winning his record eight gold medals to his boyhood pool. He and his longtime coach Bob Bowman purchased the business end of the pool and club, which has been designated an Olympic training facility.
Phelps has not yet revealed which races he'll enter in London, but his coach said there is one criterion for the choice.
"He won't swim in an event in London that he won't have a chance to win," Bowman said.
Like everything in Phelps' wake, the NBAC gala that is held every four years has grown.
The event used to be held at Meadowbrook itself, in a giant tent over the outdoor pool before it was filled for the summer, said John Cadigan, NBAC's director of operations.
"It was a party in the pool, literally," he said.
This year, the gala moved to the football stadium, "kind of following with Michael's stated desire to grow the sport," he said. "We're physically taking the event outside the pool."
Among the NBAC alums expected to attend are Beth Botsford, the 1996 double gold medalist; her teammate in the Atlanta games, Whitney Metzler; Jill Johnson Chasson, who competed in the 1992 Olympics, and Baltimore's first Olympic gold-medal swimmer, Theresa Andrews of the 1984 games.
"It's nice when you get the alumni with the current athletes and parents and coaches, and we can celebrate what we've accomplished," Cadigan said.
The gala raises money, from individual $150 tickets to the top sponsorship level of $30,000, for NBAC's endowment fund. The fund supports NBAC's teams and training for their coaches, helps keep tuition stable and goes to charitable efforts such as the Baltimore Special Olympics.
Cadigan said Meadowbrook is unique in that it is both a high-level training facility — it is a designated Olympic training venue — and a recreational pool, something that requires a certain balancing act. NBAC rents Goucher College's pool for some practics so that the families who join for the summer and casual swimmers don't get pushed out by the hard-core athletes.
Phelps' fame has had the positive effect of raising the pool's profile, he said, but "it can also scare people away who think you have to be an Olympic swimmer to come here."
"It creates a buzz when he's training here," he said. "But it's also a sanctuary for him. He can go through the lobby without being bothered, change in the locker room, just talk about the Orioles and the Ravens. He doesn't have to have a public persona here."