In 21 years of attending concerts, I cannot recall ever seeing an opening act that grabbed my attention to such a degree that I actually considered that it might overshadow the headliner. That changed on Tuesday night, when I witnessed a miraculous set performed by tUnE-yArDs at the Paradise Rock Club in Boston. From almost the very second that she walked out onstage, Merrill Garbus (lead vocals, ukelele and drums) exhibited uncommon command of the audience's attention. Her unique stage presence combined familiar indie-pop girl cuteness with a raw power that brings to mind strong female vocalists such as Etta James-and this woman is definitely listening to the blues. This arresting brew of brazen sass and deceptive meekness was reflected in both Garbus' gestures and her sound. Opening her first song with a looped repetition of gentle, Lion King-esque "kee-kee ka-ka" chirps, she then launched into a forceful reproach: "I'm not your fantasy girl." As she belted out the lyrics in what can only be appraised as an incredible voice, her eyes widened as though plotting some horrific punishment for her imaginary lover. Banging on the drums with fury, Garbus effectively lifted her initial veneer of timidity and instead confronted the audience with the image of a strong-even murderous-woman.Gender analysis aside, tUnE-YaRdS are simply a lot of fun to watch. In addition to many moments of comedy, the set's extensive use of looping techniques presented a chance for the audience to watch a song being built up one element at a time-a phenomenon that is far more entertaining when viewed live than when simply heard. Throughout the opening performance, the entire venue seemed bent on Garbus' every motion and utterance; when she mentioned that she had only brought 30 CDs with her for sale, the crowd was visibly disappointed.

Obviously, this memorable show-within-a-show set the bar rather high for the Dirty Projectors, whose highly acclaimed album, Bitte Orca, came out in June. After the six members of the band took the stage, they launched straight into a version of "No Intention" that felt slower than the album version and seriously lacked in energy. It seemed, for a moment, that the headliners, enjoying a comfortable reputation, would actually pale in comparison to their obscure opener. But this prediction was quickly shown to be just silly. On the next song, "Remade Horizon," the enthusiasm picked up considerably; during the technically remarkable bridge, the two guitarists engaged in a sort of jig jam with evident enjoyment.

Even more impressive was the way in which, beginning with this song and continuing throughout the rest of the show, the three female vocalists nailed their insanely challenging harmonies, flawlessly recreating the sound from the studio. The Projectors' unique sound is chiefly characterized by their "hiccup" vocals, a style that takes apart the melody and moves each individual note from the mouth of one singer to the next along a sort of singing assembly line. As unsettling and beautiful as this feature can be on the album, the experience of seeing it live is mind-blowing; the audience member follows a string of notes passed like a Nerf ball around the stage, seamlessly developing into a coherent (and often complex) melody.

After running through a few more songs off of Bitte Orca-"Temecula Sunrise" and "Fluorescent Half-Dome"-front man Dave Longstreth led the band into several rowdy renditions of some of their earlier material. "Gimmie Gimmie Gimmie," from Rise Above (2007), gradually grew from a soft opening to a powerful, beat-heavy jam that had the entire crowd moving. The players were manifestly less self-conscious on these less demanding (and heavier) earlier tunes and attacked each part with an ease borne of the muscle memory that comes with having played them for two years. Attack gave way to all-out abandon when several minutes of high-volume distortion punctuated the electric performance.

After that ear-splitting meltdown, the Projectors gratified the audience by taking a break from noise. Four of the band members left the stage, leaving Angel Deradoorian to sing the understatedly beautiful "Two Doves" to Longstreth's acoustic accompaniment. After a rendering of "Spray Paint the Walls" that surpassed the studio version, and a well-received execution of "Cannibal Resource," the Projectors sealed the night with the crowd-pleasing "Stillness Is the Move." Despite the sold-out venue, the cramped audience danced over a vigorous beat while vocalist Amber Coffman hit every high note spot-on. The band members, so often criticized for their noticeably distant and detached attitude while performing, smiled and laughed with each other. Already having demonstrated their awesome talent as musicians, they had plainly shed their discomfort as a live act. With any luck, the Dirty Projectors will be a group that we can see in concert for many years to come.