Galactic. L-R: Robert Mercurio, Ben Ellman, Rich Vogel, Jeff Raines, and Stanton Moore. (Zack Smith)

How is it possible that it took famed New Orleans funk conglomerate 18 years to release their first Mardi Gras album?

Set to drop on Fat Tuesday, “Carnivale Electricos” is nominally a concept album about Mardi Gras and its Brazilian counterpart Carnival, but, like all Galactic offerings, it’s actually a polyglot party disc, one that takes a leisurely tour of the musical back alleys of Louisiana and Brazil.

A roaming street party and a Lonely Planet travel guide wrapped into one, “Carnivale Electricos” is tireless and exhausting, a riot of disparate genres and influences swathed in horns and ’90s hip-hop beats, then shot like confetti out of a cannon.

It contains multitudes of guest stars both familiar (like Cyril and Ivan Neville, who show up on the buoyant, brass-happy “Out in the Street”) and unexpected (like NOLA rapper Mystikal, semi-fresh from his prison stint and growling his way through the cheery “Move Fast” alongside local rapping legend Mannie Fresh).

Some of “Carnivale Electricos” sounds like what would have happened if the Dave Matthews Band recorded a Putumayo sampler in 1994, but most of it is joyous and inventive.

Galactic's album ‘Carnivale Electricos.’ (Courtesy of Anti- Records/Courtesy of Anti- Records)

Its finest tracks, like a hip-hop/samba cover of Sérgio Mendes’ Carnival staple “Magalenha” and the sublime “Guero Bounce,” blur the divide between continents so effortlessly it seems to have never existed at all.

— Allison Stewart