The song mentioned by gillymor is "Early One Morning" (Roud 12682). I hadn't realised it was from this period, but it was. Its known from "Some Mothers do 'ave 'em" as well as Poldark, but I have known it far longer than that. Maybe we sang it at school, or maybe Grainger's arrangement used to be broadcast on the Light programme (predecessor of Radio 2). But I definitely know it from my childhood.