The Fishtank Ensemble takes its name from a club called the Fishtank in Oakland, California. When they come to the Ark September 1 (see Nightspots), they’ll be bringing a style of music that hasn’t been heard much in Ann Arbor, although examples occur in the songs of the unclassifiable Orpheum Bell and in the playlists of Yalcin Yanikoglu’s fabulous Dromedary Express show on WCBN-FM. It goes by the name of Gypsy music, but that name denotes something with at least three separate stages of development, and it’s the most recent stage that we haven’t seen much of until now.

The first stage is the traditional music of the Romani people, also known as Gypsies, which absorbed influences from the countries where the Romani lived. The second is a version of that music developed for use in the coffeehouses of Vienna and other Central European centers, inflecting a small string ensemble with Romani scales and playing techniques. Finally there’s a line of essentially Western styles that have been given a strong Gypsy flavor: first jazz, in the music of Django Reinhardt and his followers, then more recently, pop, rock, and punk.

Fishtank, as the group is called, draws liberally on all the variants of this latest stage. The band consists of players from all over the U.S. and European maps who mix up and speed up the music their ancestors made in old Vienna. Much of their music is propelled by a truly infectious slap bass player. With the addition of a female vocalist, Ursula Knudson, who can handle everything from the little-girl delivery of contemporary dance pop to operatic flights, they bring a large range of music into the Gypsy orbit. Their latest album, Woman in Sin, includes Gypsy takes on rhythm and blues (Little Willie John’s much-covered “Fever”), flamenco, and a high-speed collision of tango and Serbian dance in “Opa Opa.” Their earlier Samurai over Serbia album added yet more exotic elements to the mix.

But it’s energy, not stylistic pastiche, that’s most characteristic of this hugely enjoyable band. This music is a great deal of brash fun, and Fishtank has been gaining popularity. High-energy Gypsy-flavored modern styles have been common for a few years in New York, and more recently on the West Coast. Now they’re here, and the Fishtank Ensemble’s show ought to bring some interesting fans out of their corners.