In addition to its other rewards, last year’s Merola Opera Program included early notice of the arrival of a major vocal talent, in the person of soprano Julie Adams. Yet perhaps the most striking aspect of Adams’ artistry was her combination of plush tone and seeming effortless vocal power. Especially in the more expansive and dramatically charged parts of her recital, she lofted potent, long-breathed melodic lines that seemed to swell and fall with cunning naturalness. [...] “Chère nuit,” a luxuriant hymn to nightfall by Bachelet — who was Strauss’ exact contemporary — called for many of the same skills, including an ability to cloak steely, tireless delivery in a layer of vocal velvet. Three Korngold songs also drew from the Strauss playbook — particularly “Was du mir bist” (“What Are You to Me?”), which showed off Adams’ remarkable ability to sustain an extended melody and then turn up the intensity even further at the apex. [...] a set of German songs by Grieg found her in reveling in the folklike charm and simplicity of the material.