Trying to classify Thievery Corporation is like trying to make the most important decision of your life: right when you think you’ve made up your mind, something gets thrown into the mix to make you second guess everything you had been so sure of. During their almost three-hour sets on December 21, 22, 23, and 24, in front of four packed-house 9:30 Club crowds, Thievery had a little something for everybody.

“We haven’t been back in two years, and it’s always nice to get back here and play,” says producer and founder of Thievery Corporation, Eric Hilton. Despite the early hour (10:00 a.m. on a Friday), Hilton has been at work for hours already. After a decade with Thievery partner Rob Garza, Hilton says it has gotten harder and harder to continue the creative process as a duo. “We’re in a period now of working less together, so when we come back we can really open the gates,” says Hilton, “but it’s important that we keep our ego in check.”

At the 9:30 Club, that ego manifested itself in spectacular form. The two took the stage with, at one point, over six other musicians and a belly dancer. Garza and Hilton didn’t leave the turntables, though, while both worked on sampling, and laid down keys and beats, respectively. The performance, which was rich with music from quite a range, was one of the most extraordinary the 9:30 Club has recently seen. With constant psychedelic images being projected onto a huge screen behind their elevated platform, Thievery Corporation provided the hippie-meets-hipster audience with a vast sampling of their catalogue, from the more reggae influenced “Spliff Odyssey,” to the ever-famous, Sitar-driven “Lebanese Blonde,” to the funky electronica of “Holographic Universe.” By the end of the show, head spinning from the combination of cigarette smoke, sweaty dancers, and flashing lights, one couldn’t help but feel at least a little thankful to make it back out the fresh air.

Over the years, Thievery has worked with dozens of different singers, both incredibly famous (see: David Byrne) and less well known (see: Pam Bricker, who Hilton lauded as an incredible singer), but Hilton says that they preferred working with lower-profile artists, because it allowed him and Garza to have more creative freedom (he also insists that they highly valued the creative input of all artists, both big and small).

Thievery Corporation continues to explore new means of musical expression in every album they release, so classifying their kind of music takes more than one or two words. Electronica-funk-reggae-hiphop-world might do the job, but it hardly seems fair to limit the expanse of Thievery’s creativity to those five genres combined. So, when classifying Thievery Corporation, just like admitting defeat in the face of an important decision, there is no conclusion to reach other than “Unclassifiable.”