correction
A previous version of this article misspelled Mary Cardwell Dawson's name. This article has been corrected.
The best parts of “The Passion of Mary Cardwell Dawson,” presented Friday at the Kennedy Center’s Terrace Theater by Washington National Opera, are when the lines blur between its subject and its star, mezzo-soprano Denyce Graves.
Graves may be a far more familiar name than her titular character in this “play with music,” created by Kennedy Center composer in residence Carlos Simon and playwright Sandra Seaton, but Dawson’s time in the spotlight is long overdue.