As the Met concludes its free screenings of recent HD movie-theater broadcasts in Lincoln Center Plaza, the focus is on the star soprano Anna Netrebko. She shows off her comic side in Donizetti's "L'Elisir d'Amore" (on Friday) and "Don Pasquale" (on Saturday) before turning melancholic in Tchaikovsky's "Eugene Onegin" (on Monday). The baritone Mariusz Kwiecien is her potent partner in all three. On Sunday the tenor Jonas Kaufmann stars in Massenet's "Werther." Not one of these four productions, it should be said, is very interesting, but the singing is often memorable.