Vocalist Theo Bleckmann (pictured, left, with percussionist and composer John Hollenbeck) is one of the most flexible and uncategorizable figures on the New York scene; since the mid-90s he’s been doing his thing in a niche of his own invention, somewhere between jazz, cabaret, classical, experimental, and improvised music. He’s got a strong, precise voice and impeccable pitch control, and though I don’t like everything he does by any means, I can’t help but admire his range and curiosity. I can’t think of another singer who can wade into a Broadway songbook one minute and sound like he’s in Sigur Ros the next.

In the past few years he’s released a string of disparate albums for the German label Winter & Winter. On Las Vegas Rhapsody (2006), a collaboration with Japanese pianist Fumio Yasuda and Swiss orchestra Kammerorchester Basel, he sings American pop standards like “You Make Me Feel So Young” and “You Go to My Head,” delivering more or less straight-ahead renditions atop lush instrumental arrangements. It’s not exactly my cup of tea, but Bleckmann’s rich voice gives the melodies a rarefied dignity they rarely achieve in the mouths of piano-lounge singers.

More my speed is his next effort, Berlin: Songs of Love and War, Peace and Exile (2007). He’s accompanied again by Yasuda and this time by a deft string quartet that includes violinist Todd Reynolds (Bang on a Can, Steve Reich, Ethel); Bleckmann sings a selection of German art songs from the Weimar era (Brecht, Weill, Eisler, Schwitters, et al) in his native German. The material is a perfect match for the singer’s theatrical sensibilities, and his sly wit gives it a slightly transgressive bite despite the tastefulness of the settings.

More recently Bleckmann collaborated with New York jazz group Kneebody on Twelve Songs by Charles Ives. Kneebody gives these art songs a beguiling variety of treatments–sparse but inventive arrangements that create tension not only between the vocal melody and the backing rhythms but also within the harmonies Bleckmann and the band generate together. Bleckmann alternates between straight readings and extended, often wordless improvisations that he weaves meticulously into the fabric of sound. Kneebody is a perfect partner for him here, since in its own work it routinely emphasizes group interaction rather than a single soloist.

Bleckmann’s latest effort–and the one most germane to the performance he’s giving here–is the self-titled debut of the Refuge Trio, his group with frequent collaborator John Hollenbeck (Claudia Quintet) and keyboardist Gary Versace. Most of the trio’s repertoire is original material–they also do nicely oblique covers of pieces by Joni Mitchell, Ornette Coleman, and Thelonious Monk–but the compositions are very open. No one seems to have more leeway than Bleckmann, who spends most of the album in wordless improvisation. If that phrase makes you think “scat singing,” put it out of your head–what he does is limn the lines of his cohorts or create stunning ethereal textures that either float above the ensemble or fill in the spaces in its sound. On this recording his vocals function like a third instrument, but he never sounds like he’s merely trying to mimic one. It’s tremendously rare for a singer to realize the potential of the voice so thoroughly.

The Bleckmann/Hollenbeck Duo performs Wednesday night at Heaven Gallery. Colorlist, the duo of Charles Rumback and Charles Gorczynski, opens.

Today’s playlist:

Belle and Sebastian, The BBC Sessions (Matador)
Fela Ransome Kuti, Alagbon Close/Why Black Man Dey Suffer (Wrasse)
Ernst-Ludwig Petrowsky & Michael Griener, The Salmon (Intakt)
Francisco Mela, Cirio (Half Note)
Jimmy Sabater, El Hijo de Teresa/Teresa’s Son (Fania)