The Metropolitan Opera continues its free nightly streams via Met Opera on Demand (search for it online). This week the late Russian baritone Dmitri Hvorostovsky and Verdi are honored: Ernani on Thursday, February 25th; La Traviata on Friday, February 26th; Un Ballo in Maschera on Saturday, February 27; and Il Trovatore on Sunday, February 28. Each performance is available for 24 hours starting at 7:30 p.m.