Songs are not what Kile Smith is known for amid a high-concept output that includes sacred choral works and new music for ancient instrument. But his 45-minute song cycle In This Blue Room, written as composer-in-residence to Lyric Fest, returns to what he calls his creative center - though in a project full of conceptual gymnastics.

Premiere performances by Lyric Fest (Friday in Chestnut Hill and Sunday at Academy of Vocal Arts) had their creative starting point in the batik paintings of Laura Pritchard, most of them portraits that suggest distant Modigliani influences refracted through a playful sensibility and rich, often-blue-based palette. Four poets riffed on the paintings and composer Smith set their work to music for two voices, mezzo-soprano and baritone, in both solos and duets.

Artistic choices could have been limited as a result. But the conceit also safeguarded against, say, another setting of Walt Whitman. And Smith, for one, pulled a large rabbit out of the hat: The last thing I expected was a jazz-hybrid idiom.

Though the components of any given song functioned in ways familiar to classical art song, those components behaved like mainstream, Sarah Vaughan-era jazz. The cycle's leitmotifs included Siobhan Lyons' recurring poem "Watermelon eyes" as well as a walking theme similar to the one in Mussorgsky's Pictures at an Exhibition that actually loped like a congenial jazz bass line. Though not improvisatory, the songs were mostly through-composed, which meant that they unfolded in the open-ended manner of improvisation.

My only point of reference is Leonard Bernstein's late-period Arias and Barcarolles, with its wide range of compositional techniques, vernacular and otherwise. With similar heterogeneity, Smith often found multiple musical incidents within a single poem. He was also content to stand to the side with the poem unfurling over simple blocks of chords, though he also went against the grain of Susan Fleshman's serious "Anima and Animus" with lighthearted jazz treatment. "You are perplexed by sadness" (by Donna Wolf-Palacio) sounded downright lounge-y. Julia Blumenreich's wonderfully dreamy "Wings" came out something like a children's story.

Any piece with such a wide-reaching vocabulary isn't likely to be fully encompassed by the classical-tradition voices of Suzanne DuPlantis and Daniel Teadt, who sounded at home only in the more traditional songs at the end. Thus, the success of Smith's more trans-genre moments was difficult to access. Moments of cramped diction, for example, might warrant compositional revision or, just as easily, need to be vocalized with more agility. Pianist Laura Ward seemed hesitant to let loose in the jazz spirit of the piece; being a conscientious accompanist, her first priority was to support rather than cover the singers.

So is the piece a fruitful new direction? An interesting anomaly? We'll see.