When we hear the phrase “love song,” it’s understandable if our minds turn to sentimentality, to hearts and flowers, to the musical equivalent of a Hallmark card. The phrase conjures up love in its warm, harmonious, gemutlich aspects. Unless the phrase is being used by Olivier Messiaen.

He described his Turangalîla-symphonie (1948), which the Chicago Symphony Orchestra will perform May 21-23, simply as “a song of love.” If so, however, this is love as cataclysm, as apocalypse. At the time of its composition, he was deeply inspired by the Tristan and Isolde myth — a myth that gives us love as an all-consuming force, a passion that carries within it the seeds of destruction — and in this work he gives us a visionary upheaval of our more timid views on the subject. It’s love that is, in his words, “fatal, irresistible, transcending everything, suppressing everything outside; joy that is superhuman, overwhelming, blinding, unlimited.”

It’s an unwieldy, delirious, ecstatic cry, calling to mind — among other things — the emotional extremes articulated by Scriabin in his more ambitious orchestral works. Both composers have located themselves at the further reaches of the human experience, compelled to speak in their highly iconoclastic languages in an effort to express the inexpressible.

The massive scope of Turangalîla, its enormous range of colors and textures, the seductive mix of strict order and dizzying chaos, seems designed to disorient. You’ll hear the influences of Debussy (Messiaen’s North Star), of Indonesian gamelan, of Edgar Allan Poe, of numerology, of the composer’s beloved birdsong. The battery of percussion includes Chinese cymbals, maracas, temple blocks, vibraphone, xylophone, celesta and glockenspiel. In the midst is a prominent role for ondes Martenot, similar to the theremin. Summoning these disparate forces and forging out of them a consistent and authoritative voice is Messiaen’s unique gift. He is unmistakable. Over the top? Extreme? Even vulgar? On occasion. But unquestionably a supremely accomplished composer in full command.

Critical to finding one’s way into the work is an awareness of Messiaen’s piety. As a devout Roman Catholic (he served as organist at Paris’ Église de la Sainte-Trinité from 1931 to his death in 1992), his understanding of love is necessarily drawn from both human and celestial sources. Love, in this case, is ecstatic and at the same time pure and innocent: absent the tormenting guilt that one finds in Wagner’s treatment of the subject in his reading of Tristan und Isolde. For Messiaen, sexual passion can be both erotic and sacred.

Messiaen describes the symphony’s fifth movement (of 10!), titled “Joy in the Blood of the Stars,” as:  “a frenetic dance of joy … The union of true lovers is for them a transformation … on a cosmic scale.” Earthly lovers, yes, but at the same time, the word “blood” can’t help but evoke Christ’s Passion as well. We are firmly in a spirit of reconciliation, of unity, of adoration.

He is then, a religious composer above all, attempting to bridge the natural and the supernatural. We find, from one movement to the next, passages of deep contemplative serenity and raucous, barbaric yelps. We hear him reaching infinitely outward and infinitely inward, toward the stars and toward the depths of the human spirit. While mesmerizing, it is a puzzling, surreal voyage, a decided step away from our ordinary experience of time. But that is one mark of a visionary composer. He can arrest our daily routines, our wristwatch-and-calendar driven lives, and introduce us to something that transcends our common experiences: a love that is mad and bewildering, and at the same time utterly sincere and reassuring.

Peter Lefevre, based in California, writes about classical music for the Orange County Register and Opera News.