The greatest musical theater stars can be so multifaceted in their talents, or so adroit at particular skills, that their pure acting chops are sometimes underappreciated. When one thinks of Kelli O’Hara, say, the first qualities that likely come to mind are a sterling soprano voice and a glowing presence. With Brian d’Arcy James, also a fine singer, there’s the comedic facility that has distinguished his performances in shows such as “Something Rotten!” and “Shrek the Musical.”