The Log Journal reviews performances presented by National Sawdust resident artists and curators only with the explicit approval of those artists, and encourages them to respond in kind.

Even for those who know and love the music of Philip Glass, the stylistic leap from the composer’s landmark first opera, Einstein on the Beach (1976), to its most famous successor, Satyagraha (1979), can seem mysterious and inexplicable. From the first, with its stream-of-consciousness, non-narrative texts and barrage of disparate, discontinuous tableaus, it feels like a light year’s distance to the next, an elegantly compressed span that, however stylized, embraces a linear chronology.

Tucked in between the two, though, is a concise, little known work that helps to bridge that seemingly enormous gap: A Madrigal Opera (1979), which Glass wrote for the Dutch theater artist Rob Malasch. Commissioned by the Holland Festival, which mounted the premiere in June 1980, the work involves a small complement of performers: a chorus that can be as small as six singers and a single violinist or violist.

Like Einstein, A Madrigal Opera is non-narrative, its texts confined entirely to abstract syllables and solfège note names (do, re, mi, etcetera). Like Satyagraha, though, its instrumentation and singing style are more conventionally those of the concert-music world, as opposed to the electrified, amplified hybrid of Einstein.

Philip Glass (L); RB Schlather (R)

Yet for all that A Madrigal Opera looks forward to Glass’s more mainstream idiom on the horizon, in its way it is far more abstract than Einstein had been. Despite being designated for the stage, the work has no plot or characters, no clear linear direction or dramatic arc, per se. Precisely how to stage the piece, Glass contends, is up to the individual presenter. As stated on the composer’s official website, A Madrigal Opera “is conceived as an abstract music theater work which would then be ‘completed’ by the various future directors. It is for this reason that though the work has a clear emotional shape, it has no specific theatrical content.”

That assignment likely would be daunting to many directors: How do you invite an audience into an opera that has no characters to relate to, no story to follow? The inventive director RB Schlather, mounting A Madrigal Opera as the final entry in his engaging, productive National Sawdust residency, approached that challenge in an artfully literal-minded way, mingling members of the stellar vocal ensemble Choral Chameleon among the audience and engulfing them all within an elegantly simple, smartly realized common frame of reference.

Entering National Sawdust’s main floor-level space for performances on April 28 and 29, you saw chairs scattered throughout the space, all facing in different directions. No stage was present to provide orientation; in fact, apart from one seat conspicuously occupied by the violinist Johnny Gandelsman, there was little to suggest anything notable was about to transpire.

As the lights dimmed, a photographic image from the street outside – low red-brick commercial buildings, with shiny white skyscrapers towering above them – was splashed across two walls framing a corner. It was exactly then that I realized I’d made a mistake taking a seat upstairs in the balcony…

…and, sure enough, when the singing commenced, it came from vocalists seated incognito throughout the audience area. No one rose. No spotlight blared to discriminate between participants and observers. If you didn’t see the faint illumination emitted by iPads bearing musical scores, you might not have known exactly which of your neighbors was singing.

If, under the circumstances, the gesture wasn’t altogether unforeseeable, the result was uncanny nonetheless. Glass’s music moved as it does (or did at that point in his career, anyway): rippling and undulating arpeggios rose and fell, rose and fell, rose and fell, shifting in direction with a rapidity that showed Glass was already moving away decisively from pure long-form minimalism. Now and again, triplet rhythms seemed to convey an appealing oom-pah-pah waltz-time rusticity.

Providing drama during the first half of the performance was a tension between Gandelsman’s muscular exertions and the cool, unblemished flow of Choral Chameleon’s singing. During a long pause in near darkness, Gandelsman was escorted offstage and the violist William Frampton came on; when the music resumed, it naturally had a duskier tone ideally suited to the darkening skies projected on the walls. (Here, too, was early evidence of Glass’s penchant for reusing effective material: One particular viola line, thrilling in its vertiginous plunging and soaring, is virtually indistinguishable from a motif that runs through the powerful “Pruitt Igoe” section of Glass’s 1982 score for the film Koyaanisqatsi.)

From a musical perspective, then, A Madrigal Opera addresses a burning question for Glass cognoscenti, and provides a good hour’s rewarding diversion for anyone – especially when performed with this much style and assurance. What made the experience truly memorable, though, was in Schlather’s simple, elegant solution to the burning question the opera poses – engaging audience members in an abstract opera by making them a part of it, literally.

(For another perspective, read Corinna da Fonseca-Wollheim’s review in The New York Times.)