Possessed of a large, rich, flexible voice that works equally well in Verdi, Wagner, and Handel, Blythe leaves all that behind to once again champion American music in recital. Her program segues from James Legg’s (not Copland’s) Twelve Poems of Emily Dickinson and Barber’s Three Songs, Op. 10, to a mixture of popular songs by Scott Joplin, Irving Berlin, and several and sundry denizens of Tin Pan Alley. From serious to slumming, or just plain delicious? We’ll know soon enough.