It was not Messiaen's aim to present a life of St. Francis in vivid scenes of worldly action. Indeed, several events in the Saint's life which would have lent themselves very well to dramatic treatment find no place here. Instead there is a series of tableaux in which, according to Messiaen's own synopsis, “one must see the progress of grace in the soul of St. Francis.” A particularly prominent theme in the libretto, written by the composer, is the essential experience of suffering as a prerequisite to joy. For Francis this meant encountering and embracing a leper, overcoming personal revulsion, and later receiving the stigmata — the wounds of Christ's suffering on the cross. The consolation and eventual transfiguration of Francis are aided by an angel, whose visits provide glimpses of the eternal joy of Heaven. A large chorus, sometimes but not always singing actual words, evokes the real but invisible presence of Christ at several pivotal moments.

The musical environment of the work is — again in a very catholic way — at once exceedingly simple and nearly impenetrable. There is not mere drama for the music to underline or evoke; instead, it has a ritual, incantatory character. Motifs are used and repeated as are turns of phrase in scripture, or Greek poetry. Most of the text is sung either as accompanied recitative or as a sort of thickened monody, in which the voice is enveloped by swaths of harmony which move with it in parallel. Singing over a differentiated accompaniment is relatively rare. Technically this keeps the voices at the forefront while allowing the aforementioned huge orchestra a vast palette of color.

Bright sounds predominate: the shrill sounds of piccolo and clarinet, the dry wooden mallet instruments, thick clouds of high strings or brass, and the eerie cries of three electronic Ondes martenot (already “period instruments” after only a matter of decades). Messiaen's lifelong fascination with birdsong finds its most unrestrained expression in this work; one might almost think he chose St. Francis as a subject just in order to compose the sermon-to-the-birds scene.

Some of the logistical difficulties posed by Messiaen are here solved brilliantly. The orchestra, even cut down a bit from the desired size of 120, is too large to fit in the pit. Five mallet instruments (a core group of xylophone, xylorimba and marimba which often play together, as well as glockenspiel and vibraphone) are arrayed on a platform beside stage left; the three Ondes and their many loudspeakers are opposite, beside stage right. The “mallet corps” has quite a bit of important music framing the scenes that merits their elevated billing (even costumed, in cassocks and skullcaps). Their prominent position does occasionally skew the balance when they have to combine with other instruments many feet lower down, however. The chorus is ingeniously placed around, behind, and within the set, as well as offstage.

Hans Dieter Schaal's set has at its center a large, noisily rotating circle which incorporates a metaphorically-correct rising path, Francis' cell, and other vaguely cruciform configurations. This is surrounded by multi-story rectangular compartments (bringing a touch of postwar Germany to 13th-century Assisi) filled occasionally with Friars or choristers.

It seems that the visual design, including the costumes of Andrea Schmidt-Futterer and the lighting of Alexander Koppelmann, made a point of leaving most of the color to the music, with the exception of an exceedingly blue angel. Fine for Messiaen, whose descriptions of his own music are replete with colors for harmonies and timbres. Fine also for the Friars and their historically plausible habits. But the silver trenchcoats and fedoras worn by the chorus as they formed a parade of travelers in the first scene? Symbols merely of worldliness, according to the ever-helpful press kit.

It annoys you, but you can buy it; and so it goes with so many other little visual details of the production. There is the angel with one wing (the left wing, naturally — for Houston Grand Opera, would they switch?); the nonsensical neumes (medieval musical notation) painted on a scrim for a scene change — you know, just for a sort of period feel, no matter that it was utter gibberish; the giant cut-out dove, looking like a well-intentioned Sunday School art project, projected over texts of St. Francis in faux-antique calligraphy. Genuinely shameful, by contrast, was the opening film clip of the Basilica at Assisi's ceiling falling in during the recent earthquake, re-run CNN-style. That was a gratuitous little push of the audience's memory button, aimed perhaps at a more recent visual image of a massive building collapse.

Would that the over four hours of music were so consistently engrossing as to banish these little affronts from the memory entirely, but as on Francis' soul's journey, there are vicissitudes. Granted, the work's very essence forces one to re-imagine the entire context of musical time, and few composers have evoked a realm beyond the temporal as effectively as Messiaen. The most other-worldly music — that of the angel — is ineffably beautiful and touching. Laura Aikin sings it with a radiant and pure tone, and exudes a correspondingly lyrical stage presence. Likewise the chorus' Christ-presences were very moving.

The most “active” scene, in which St. Francis embraces the Leper, who is miraculously healed, was by far the most compelling. It brought all the elements of suffering, joy and transformation together. Chris Merritt's performance as the self-pitying, then repentant Leper was suffused with an authenticity of suffering and radiant redemption (this put the Saint's numbing stasis into even greater relief). Even the seemingly tangential fourth Tableau has real urgency. Here the Angel, trading preposterous blue bodysuit for preposterous blue fedora, trenchcoat and wing-pack (ahh . . . this means she is in earthbound disguise! I get it!), feistily debates with two of the Friars.

Elsewhere in the temporal realm, however, timelessness teeters closer to endlessness. The character of St. Francis poses the problem; in order to portray his transformation, Messiaen has him soliloquize a lot. Sometimes, he is provided the foil of a brother Friar to put a sort of temporal check on his meditations, but for very long stretches it's just Francis and us. And of course, he is not really talking to us. It can be a bit of a grind.

The second Tableau, for example, has Francis inside his tiny cell reciting his famous words in praise of all creation. Perhaps Messiaen thought that, in the context of a joy-through-suffering message, it would look unseemly or inconsistent to have Francis appear at all happy; in any case, he has Francis intone the words slowly and sparsely to the accompaniment of extremely lugubrious music. Director Nicolas Brieger has Francis appear to be in particularly intense physical distress.

It is the 40-minute-long sixth Tableau — the much-vaunted sermon to the birds — that most tries the patience. Here Messiaen is at his most self-indulgent, the more so for crafting his libretto so as to make the enumeration of all sorts of exotic birds a theological necessity. He was just a bit nutty about the bird thing. The sympathetic listener will regard this trait with the tolerance and affection one might bestow on a relative just a bit too interested in Civil War memorabilia, as he shows you videos of the most recent re-enactment he attended. As the scene progressed, and the series of exchanges between Francis and Frère Massée (“what bird is that one?” “The Wren” — but expanded to several phrases) continued, the audience started to calculate the number of birds contained in the Sibley guide, multiplying by a few minutes per bird, subtracting the number of minutes since their last cup of coffee, et cetera.

The actual bird music, eventually performed with great brio by the orchestra (the piccolos deserve special recognition) and under the sure control of a most un-octopus-like Donald Runnicles, was a delight. The presence onstage of crew personnel and staff in street clothes to listen did not have quite the intended effect of uniting all people as listeners in a spectacle transcending time and space; they were, after all, probably receiving double overtime.

A noticeably smaller audience returned for the Third Act. Here Francis receives the stigmata, whilst standing on what can only be decorously described as a long member, rising gradually to fifteen degrees above the horizontal, and falling again. He is subsequently deposited at the foot of the stage, where he sings the entire last Tableau lying on the ground. As Saint Francis, baritone Willard White gives a performance astonishingly unfettered by the hopelessly limited range of grimacing and staggering gesture his character is afforded. Onstage for most of the opera, he exudes a mighty presence, evoking piety and, well, yes, sanctimony. His brother Friars, notably Johannes Martin Kränzle as Frère Léon, Gran Wilson as Frère Massée, Jay Hunter Morris as the officious Frère Elie (fedora, no tonsure) and Gabor Andrasy as the aged Frère Bernard, were spirited foils for the Saint and each other.

Throughout the evening, the performance was of an amazingly high standard. Occasionally one noticed a leanness in the timbre of the string chords that an extra 20 players would have mitigated; there was the odd fuzzy attack, and one upward spiraling passage for strings in particular that never quite achieved a state of grace. Yet the night was a complete triumph for Music Director Runnicles and his orchestra, and especially for Ian Robertson and the Opera Chorus. Productions come and go, but these are the true blockbuster assets of the company.

The opera continues in five more performances through next month (October 1, 5, 10, 13 and 17); despite the longueurs it is a remarkable worldly experience.