Amy Ray and Emily Saliers -- better known as The Indigo Girls -- have been at it for well more than two decades now, but the popular Grammy-winning gay icons are only now making their debut at Strathmore. And the venue's acoustically rich Music Center sounds like the perfect fit for the duo, its tight harmonies in particular -- call it "Closer to Fine," if you'd like. Atlanta's five-man pop/folk band the Shadowboxers open. Sunday, Oct. 9, at 7 p.m. Music Center at Strathmore, 5301 Tuckerman Lane, North Bethesda. Remaining tickets are $45 to $55. Call 301-581-5100 or visit strathmore.org.