“I know the doctor said this is only a bad cold,” says the patient, whose his wife stands by his bedside in a cartoon by the New Yorker artist Edward Frascino, from the age of the vinyl LP, “but in case he’s mistaken I’d like to hear side eight of ‘Der Rosenkavalier’ one more time.” The rhapsodic strains of Richard Strauss have for decades been a fixture at the Santa Fe Opera. In this summer’s Der Rosenkavalier, it’s Rachel Willis-Sørensen who leads off the trio that inspired the immortal caption. She sings the coveted role of the Marschallin, a sensualist on the cusp of middle age whose love life unfolds beyond the confines of her marriage of inconvenience. In Act One, we meet her in the throes of a torrid tryst with a 17-year-old Jack who is shortly to fall hard for a Jill of his own age. The lady’s meditations on the passing of time are rightly reckoned some of the most luminous pages ever written for the soprano voice. But the score’s crowning glory comes in the trio two acts later (side eight on midcentury recordings), when all three players in the love triangle meet onstage for the first time, blending their voices in overlapping soliloquies of bewildered wonderment. Joining Willis-Sørensen this season are the mezzo-soprano Paula Murrihy as Octavian, the Marschallin’s underage ex, and the high-flying, crystalline Ying Fang as Octavian’s new love Sophie (except on closing night, when Liv Redpath steps in). Under the starry dome of the New Mexico sky, it’s a good bet they’ll dispense sheer ecstasy. Even if you don’t have the sniffles, bring Kleenex. —Matthew Gurewitsch