It is a brave artist indeed who tries to capture the complex nature of the career of Carly Simon. That is the task that Marnie Klar sets for herself in her show MARNIE KLAR SINGS CARLY SIMON, which had an encore performance Monday evening at Don’t Tell Mama. It is clear that Ms. Klar has great respect for Carly Simon and possesses a great deal of knowledge about how her songs came to be. Like Simon, she is quite a beauty and has a great dexterity with language. She also shares with Simon a wide emotional range.