Taking cues from the late Argentine tango wizard Astor Piazzolla, the three conservatory-trained East Coast musicians who make up the Tin Hat Trio continue to tinker with "world music" -- and boy, do they like to tinker. Recorded almost completely without overdubs, Helium marks the skilled followup to the group's 1999 debut, Memory Is an Elephant, and finds the artsy cafe orchestra whittling its sound even closer to the bone. Predominantly a guitar-violin-accordion lineup featuring Mark Orton, Carla Kihlstedt and Rob Burger, the outfit peddles infectious acoustica that blends not only nuevo tango, but bluegrass, contemporary classical, hard jazz and Eastern European folk music. And sometimes, tricksters and pundits, it happens all at once. The old-world lament of "A Life in East Poultney" borrows from the Yankee banjo plus an ominous creature called the marxophone -- whatever that is. Oddly metered syncopations introduce "Beverly's March," a staggering traipse into a dark but funny situation in which the music is twiddled, scraped and bent out of shape. Seemingly disdainful of a leading voice on "Bev," the Trio plays acey-deucey with itself, becoming alternately loud and quiet, ignoring melody while charming the pants off anything that might go bump in the night. When melody is fleetingly employed (the hoedown of "Scrap," the Fellini vibe of "Esperanto," the dizzy circus of "Big Blue House"), the results feel cinematic. Best of all, every listener gets to engage his very own inner cinematographer. On "Slip," for example, scratchy Morse Code transmissions combine with a Viennese-sounding waltz to produce something one might imagine in a film noir war setting -- say, black-and-white Nazis in a bunker getting drunk. Or Eva and Adolf doin' it one last time. Maybe Marlene Dietrich brushing her hair, or some bloated Bavarian eating schnitzel. Delicious schnitzel. The meaning of those many dots and dashes, dear listener, is entirely up to you. At the disc's end, the title cut resurfaces for a drastic overhaul; it's a dreamy reprise featuring the work's only vocals, those of beloved junkman Tom Waits. "This blinding kiss," he whispers ever so distinctively, "breathes helium/into my heart/and erases/the embraces/of all of the lovers." Waits's cameo is the glittering jewel in an already nifty crown.