Sean Hayes in “Goodnight Oscar”

In the new Broadway play “Good Night, Oscar,” Sean Hayes, the Emmy Award-winning star of “Will & Grace,” stars as the witty and eccentric musical star Oscar Levant, whose struggles with mental health and addiction to drugs would come to the fore. -and-center during a 1958 appearance on Jack Paar’s “Tonight Show.” Correspondent David Pogue talks to Hayes about conjuring Levant onstage; and with Pulitzer Prize-winning playwright Doug Wright about darkness at the center of the play’s central figure.