Mardi Gras revelers draped themselves in beads, masks, hats, boas, and vests. Some joined the conga line that snaked offstage into the crowd, led by Lamonster trombonist and band leader Tad Mondale playing that old standard, “When the Saints Go Marching In.”

This year’s Mardi Gras fete at the Garage downtown marked a harmonic convergence of Fat Tuesday and Super Tuesday, so it seemed appropriate that Mondale, the son of the former vice president and failed presidential candidate Walter Mondale, would lead the procession.

Mondale grew up on Lamont Street NW; hence the band’s name. After picking up the trombone in the fifth grade, Mondale grew to worship Louis Armstrong, the Rebirth Brass Band, and Kermit Ruffins and the BBQ Swingers. Growing up in Mount Pleasant, with its huge Central American population, he also absorbed the sounds of Latin jazz.

The two influences fused into Lamonster several years ago when Mondale found Andrew Bolton, a local funk keyboardist, and blended Bolton’s sound with his own. The band’s New Orleans tilt began to predominate last year when Mondale met New Orleans legend James Andrews at the State Theatre in Falls Church. Andrews had brought along his 14-year-old brother, Troy “Trombone Shorty” Andrews, whom Mondale hails as a “musical deity.” The Andrews brothers and Mondale’s band have gigged mostly in the Big Easy, opening for the likes of Dr. John, Cyril Neville, and the Wild Magnolias at the House of Blues and the Boom Boom Room. Now Lamonster and the Andrewses are launching a five-city “Dirty Rice” tour this summer.

From set to set Tuesday night, it occasionally seemed as if two distinct bands—one bossa nova, one jazz-funk—were playing. But once Lamonster got the mix right—with Nicki Gonzalez, a fast-rising local diva, joining the vocal section, and Nelson Cruz on timbales doing his darnedest to fuse the two sounds rhythmically—there wasn’t much for Mondale to do but blow his horn and toss Mardi Gras cups into the crowd.—Patrick Tracey