Baritone Dmitiri Hvorostovsky, who has been battling a brain tumor that forced a hiatus, surprised the 2017 Metropolitan Opera Gala audience with a performance of “Cortigiani, vil razza dannata" from Verdi's "Rigoletto." Read more here: http://www.wqxr.org/story/dmitri-hvorostovskys-surprise-performance-met-opera-50th-anniversary-gala/Video credit: Metropolitan Opera