Girl Talk’s performance at the 9:30 Club last night could best be described as the ultimate six-year-old’s birthday party, but in the best way. The musical persona of Pittsburgh’s experimental musician-turned-DJ, Gregg Gillis, Girl Talk has become synonymous in recent years with “party” for a slightly older demographic. His performances, from clubs to festivals, are short and sweet and littered with party favors. It’s the odd man out who does not have a stack of glow bracelets to wave around or a balloon to clutch. There is no petting zoo onstage — that’s reserved for the audience below. Instead, Gillis brings out his confetti cannons, inflatable shapes, LED displays, giant air-filled pouches of confetti and helium-filled balloons that float upward when pierced. It may be a blessing his sets clock in at just over an hour — anything longer and his fans might faint from overstimulation.