The event capped a day of ceremony, with O'Malley's swearing-in and address in Annapolis.
The Saw Doctors, an Irish rock band, gave a repeat performance at the ball. And the usual suspects -- cabinet secretaries, county executives, lawmakers and administration and campaign staples -- made appearances.
In a heavily staged exchange, Baltimore Mayor Stephanie Rawlings-Blake implored O'Malley to play a set with his band, O'Malley's March. The governor faux hemmed and hawed and then, no surprise, rolled up his sleeves and grabbed a guitar. (First lady Katie O'Malley told the crowd, "He's such a showboat.") His first song: Johnny Cash's "I Walk the Line."
One surprise attendee: former Baltimore Mayor Sheila Dixon, who resigned about a year ago after a conviction and a plea in a gift-card misuse case. She held court at a stand-up table in the middle of the floor, greeting old friends and employees. Also swirling about was "Developer B," Patrick Turner, a star witness at Dixon's trial.
Guests' $75 tickets gave them access to an open bar of beer and wine -- no spirits -- and a buffet. The venue is a training facility for the Maryland National Guard also used an emergency shelter. Ticket sales and sponsors funded the event, said O'Malley spokesman Rick Abbruzzese.
Oh, and that guy in denim? Department of Public Safety and Correctional Services spokesman Rick Binetti. He did pair the jeans with a snappy blazer.