The Boston Baroque will present Monteverdi’s “L’incoronazione di Poppea” with a starry cast. The company announced that soprano Amanda Forsythe will perform the title role alongside countertenor Anthony Roth Costanzo making his Boston Baroque debut as Nero. The cast will also include contralto Emily Marvosh as Ottavia, Ryan Belongie as Ottone, tenor Brian Giebler as Arnalta, bass Kevin Langan as Seneca, {…}