Valentine’s Day remains two weeks away, but its spirit kicks in early with Street Theatre Company’s presentation of A.R. Gurney’s popular two-person show about a long-distance relationship. The story predates email, of course, so the actors read from actual letters — remember those? — as they are exchanged over a 50-year period, capturing the duo’s hopes, dreams, victories and defeats with each correspondence. Each performance features a different cast. First up are Layne Sasser and Ken Jackson, both popular and well-known veterans of many Nashville stages. The second performance finds its co-stars, Ruby Amanfu and Francis Rodino, moonlighting from their better-known careers as musicians. Amanfu has appeared on NBC’s The Sing Off, has toured with Jack White, and has authored songs recorded by Kelly Clarkson, Justin Guarini and others. Singer-songwriter Rodino, meanwhile, has performed extensively throughout Europe and is currently based in Music City, where he’s working on material for the follow-up to his debut folk/pop/rock album Circles & Squares.