Erin Morley and Vlad Iftinca at Weill Recital Hall It rarely bodes well when an administrator appears onstage before an opera or recital, but on Friday night at Weill Recital Hall, Jeremy Geffen, Carnegie Hall's director of artistic planning, announced that Erin Morley had decided to perform despite being ill. Ms. Morley, a notable young coloratura soprano who is currently singing the Rhinemaiden Woglinde in Wagner's "Ring" cycle at the Metropolitan Opera, still sounded remarkably good, though occasionally tentative in the first half of the program. She omitted Haydn's "Berenice, Che Fai" and Rossini's "Danza," two of the more athletic works scheduled, as well as Poulenc's "Trois Poèmes de Louise de Vilmorin." Instead she opened with three songs by Schumann - "Der Sandmann" (Op. 79, No. 12), "Des Sennen Abschied" (Op. 79, No. 22) and "Liebeslied" (Op. 51, No. 5) - that showed her distinctive, silvery soprano to fine effect. Vlad Iftinca, a staff pianist at the Metropolitan Opera, proved an eloquent collaborator throughout the concert, which also included a poignant rendition of Rossini's "Mi Lagnerò Tacendo" and a characterful interpretation of Rossini's "Fioraja Fiorentina," complete with illness-defying radiant top notes. After intermission came Barber's Four Songs (Op. 13). Ms. Morley's dramatically hued rendition of "Sure on This Shining Night" proved the highlight of the cycle. She also sang expressively and with commitment to text in Rachmaninoff's Six Songs (Op. 38), which concluded the program. As an encore she offered Schumann's "Der Himmel Hat Eine Träne Geweinet."