Having two singers play the same character is not quite a novelty in a work of music theater. Stephen Sondheim used the device, four times over, in his 1971 show “Follies.”

But composer Laura Kaminsky’s decision to use a baritone and a mezzo-soprano to portray the central character in her opera “As One” is certainly unique. Because that character, Hannah, is transgender.

The opera follows Hannah’s journey from a male to female identity, unfolding over an interlocking sequence of 15 scenes, spanning just 80 minutes. Kaminsky’s piece counts as the opera world’s first depiction of a transgender character, with each singer representing a different aspect of Hannah’s psychology. “As One” has notched more than a dozen new productions since its 2014 premiere at the Brooklyn Academy of Music, a remarkable number for a modern opera.

The reason for all the buzz was clear at Skylark’s Opera Theatre’s Minnesota premiere Friday evening in St. Paul.

The action unfolded on a simple platform of stage risers, wedged against the back wall of the North Garden Theater’s auditorium. Four chairs and a handful of props served as the show’s minimal set, with video projections by “As One” co-librettist Kimberly Reed providing a contextualizing backdrop.

Behind baritone Luke Williams and mezzo-soprano Bergen Baker there was a string quartet playing Kaminsky’s score, with music director Jeffrey Stirling perched on a high stool facing them. The effect was intimate and conversational, with a feeling of emotion recollected from a position of relative serenity.

Some of the production’s scenes are anything but peaceful, however. Slithering, almost sickening dissonances from the quartet underpinned Hannah’s nightmarish recollection of surviving a hate crime attack. Earlier in the show, the post-transition “Hannah After” is aggressively throat-locked by the high school jock “Hannah Before” in an attempt to stifle her rising femininity.

More often, though, the two singers intertwined like stems on the same vine, wryly observing one another and interacting playfully as Hannah’s authentic identity incrementally blossoms.

As “Hannah After,” Baker contributed a beautifully sung performance, her bright, vibrant stage presence an increasingly indomitable presence as the opera progressed. Her final scene, set in the fjords of Norway, had a transfigured feeling to it — and an elevated sense of arrival at some long-desired destination.

Baritone Williams’ grounded vocalism and clean enunciation were an effective foil to Bergen’s more florid writing.

One major reason why “As One” works as a rounded dramatic experience is Kaminsky’s music. Combining elements of pulsing minimalism with richly expressive melody, it is exceptionally well written for the string quartet and tellingly empathetic to the voices.

Bob Neu’s direction was clear and uncluttered, though the singers occasionally looked a little stranded and short of “business,” especially when one scene shifts to another.

But this Skylark production is still essential viewing. Though transgenderism is the opera’s main focus, the show compellingly speaks to broader issues of identity and sexual politics in the social battlefield of 21st-century America.

Terry Blain is a freelance classical music critic for the Star Tribune. Reach him at artsblain@gmail.com.