Rare indeed is the artist the Metropolitan Opera dares to showcase in an unplugged recital on its mainstage, accompanied only by a piano. In truth, the 3,800-seat hall is too big by a factor of at least two for the nuances of the art-song literature—while operatic excerpts in such a space cry out for full orchestral accompaniment. For now, we’ll take it on faith that the ravishing Lise Davidsen of Norway can square the circle. Her program juxtaposes lieder of Schubert, Grieg, Sibelius, and Richard Strauss with arias by Verdi, Wagner, and Tchaikovsky. The soprano’s partner at the keyboard is James Ballieu. —Matthew Gurewitsch