Minnesota Concert Opera set a difficult task for itself. It presented opera unstaged and accompanied only by a piano and percussion. In other words, the spectacle and drama, which is a major part of the opera experience, was missing.

That said, its inaugural effort, Bellini's "I Puritani" is an ideal choice for this kind of presentation. It puts the focus on the voices, where it belongs. This is a singer's opera, providing many opportunities for vocal display. While the singers here were not always up to the demands of their roles, they were not the main problem of this disappointing evening. That responsibility fell to music director Barb Brooks.

As accompanist, she constantly reminded that the piano is a percussion instrument. Her pounding on the keyboard ceased to be even musical at times and only accentuated how anemic the chorus sounded.

Her erratic tempos were unable to maintain the inner momentum of the music, and the recitatives in particular were often plodding. She was stylistically inaccurate in not insisting that the singers ornament the repeats of their arias, as Bellini would have expected. That's the equivalent of straitjacketing jazz by forbidding improvisation.

Set at the time of the English Civil War, "Puritani" is a Romeo and Juliet story of Elvira (soprano), a Puritan, and Arturo (tenor), a Cavalier and supporter of the beheaded Charles I. Riccardo (baritone), a fellow Puritan, is also in love with Elvira, creating a typical love triangle. Elvira's uncle, Giorgio (bass) rounds out the leads.

As Arturo, Ben Gulley was the standout performer. Though he seemed incapable of singing softer than forte, he was thrilling and added a needed element of passion to the staid proceedings.

Tracey Engleman brought a bright, silvery soprano to Elvira, and made short work of the coloratura. But her voice had a brittle edge to it and she was too often overwhelmed by the ensemble. As Riccardo and Giorgio, Stephen Mumbert and Jorge Ocasio were more than competent.

This is an inauspicious debut for the company, but the music is sublime and still managed to shine through.