Juilliard Opera's "Curlew River" and "Riders to the Sea" One-act operas can seem to exist via reputation and recordings only, with staged presentations few and far between. Even the very best works in the genre tend to languish, often for the most prosaic reason: if an opera is too short to sustain a full program, what can it be paired with, profitably and sympathetically? The Italian red-sauce tandem "Pagliacci" and "Cavalleria Rusticana" is an example of an unusually successful coupling, bonded by blood and big tunes. On Sunday the adventuresome Juilliard Opera fashioned a fascinating double bill from two disparate English operas that proved complementary in less than obvious ways. Probably no one would claim that Britten's "Curlew River," a 1964 church parable with a libretto by William Plomer, and Vaughan Williams's "Riders to the Sea," an adaptation of a J. M. Synge play completed in 1932, have much in common beyond their nation of origin and a watery milieu. But the two operas, mounted in Juilliard's Rosemary and Meredith Willson Theater, are rooted in bonds between mothers and sons. Britten, inspired by a Japanese Noh play he saw in Tokyo in 1956, recounts the tale of a madwoman traveling by ferry among a group of male pilgrims to the tomb of a kidnapped boy. Vaughan Williams, setting Synge almost verbatim, describes an Irish mother's loss of her last son to a stormy sea, his father and four brothers having perished similarly before. John Giampietro, the director, further linked the works with sets of ingenious economy, designed by Alexis Distler. Action took place on and around two low wooden platforms with hinged lids and rollers, serving as a ferry in "Curlew River" and a homestead in "Riders to the Sea." Paper lanterns shaped like cottages represented quaint villages while alluding to Japanese influence; overhead a canvas drape on pulley wires served first as a sail and then, perhaps, as an overcast sky. Of the two works the Britten was the more successful realization, its prismatic colors and haunting spirit aptly conveyed by a splendid instrumental ensemble stationed in two corners of the room. Though the work requires no conductor, Mark Shapiro subtly coordinated the performers. Among a strong cast, Kyle Bielfield stood out as the Madwoman, a demanding tenor role Britten originally created for Peter Pears. Singing superbly and acting with intensity, Mr. Bielfield pitched his portrayal ideally between oddity and piteousness. Having the flutist Daniel James leave his seat to stalk Mr. Bielfield in the stark, fluttering "Hoping, I Wander'd On" was an inspired touch, and the moment when the Madwoman encounters the spirit of the kidnapped boy - her lost son, it happens - was depicted dazzlingly. Davone Tines, a bass-baritone, was a noble Abbott. That "Riders to the Sea" fared less well was mostly because of a piano reduction that sacrificed Vaughan Williams's mottled blue-gray orchestration and wind-machine gusts. Though it was deftly and sensitively played by Adam Nielsen, the results could feel monochromatic and lugubrious. Still, this majestic score, with its intimations of Vaughan Williams's haunted Sixth and Seventh Symphonies, aptly conveys trepidation and elemental awe, and the cast members - particularly Lacey Jo Benter, a promising young mezzo-soprano, as the family matriarch Maurya - did their jobs well. The program repeats on Tuesday and Thursday at the Juilliard School's Willson Theater, 155 West 65th Street, Lincoln Center; (212) 769-7406, juilliard.edu.