I take it they weren't going for a Bob Dylan "sound alike" (a la "Movin' Out") and cast Arden to make sure the audience can actually understand the lyrics (which are brilliant, incidentally).
"What a story........ everything but the bloodhounds snappin' at her rear end." -- Birdie
[http://margochanning.broadwayworld.com/]
"The Devil Be Hittin' Me" -- Whitney