What I remember about first seeing the Rebirth Brass Band is that they were just kids and they were wholly portable.

Unlike most other musical outfits in New Orleans, that had to be plugged in, tuned up and fully sound checked before any show could start, here was a band so close to their marching roots that they could come right into a venue while playing and pretty much be the same band – all brass and drums and swagger – and keep up that authentic sound from the floor, the stage, the balcony or wherever they chose to perch.

Mixing the traditions of the fourth line, the discipline of high school marching corps, essentials of funk, intricacies of Dixieland and flight of jazz — all flying to the precise snap of the drummers and the bottom served by a tuba — they were the portable sound of New Orleans, adding a freshness and verve to very old (and often much slower paced) forebares.

Now they’re out celebrating their 30th year, on their way to New York to record a funkier Super Bowl theme for the upcoming event at the Superdome, and so proud of their Grammy this year for Best Regional Roots Music Album it’s surprising they don’t wave around the statues on stage (though one invited everyone to his house to see it).

But they’re just as tied to their microphones and other tethers as any conventional group at the 9:30 Club, and owing from the large throngs that came out to party with them Thursday, maybe they needed the amplification. There’s a lot more vocals than I recall from the group that still relies a lot on sassy instrumental arrangements – a lot of call and response and unnecessary branding of the band (“I say Re, you say Birth!”) (we know the name of the band by now). It made it confusing for the sound man, who’d typically turn down the levels when they were blowing horns into them, then forget to turn them up when they were saying something into them. Some had two microphones for this very purpose, I imagine, but kept mixing up which one was the speaking mic and which one the horn mic.

None of this really mattered. They began with “When the Saints Go Marchin’ In” as a given, as much for the NFL team as for city tradition. “Now that’s out of the way,” one said, before they got into their marvelous reworkings of songs into a brass band funk melange that rendered “Don’t Stop Til You Get Enough” and “Billie Jean” into a delicious MJ medley; paid homage to their New Orleans forebears with Professor Longhair’s “Mardi Gras” and Fats Domino’s “I’m Walking” and then let loose into their own originals that alternated sweetness with badass brass complexity.

Once just kids picking up on Crescent City traditions like osmosis, Rebirth has its own traditions — Kermit Ruffins was an original member, since departed; Trombone Shorty is a cousin of the Glen Andrews, who with the Fraizer brothers, were there at the beginning, at Clark High School in the Treme, a musically rich neighborhood whose name is more widely known because of HBO’s fine series.

Recently on tour with the Red Hot Chili Peppers, the band included a lick from them (as well as one from Steve Miller), but otherwise stuck to some surprisingly old covers, particularly Levert’s 1087 hit “Casanova,” which they played once they invited “all the ladies” up on the stage to dance (ahtough once there, they started singing some creepy lines about disrobing).

Once, the band would have done the opposite, joined the dancers on the floor on their way marching across the floor. But again, that was nearly 30 years ago.