Before there was Glimmerglass or St Louis or even Santa Fe, there was Central City, a haven for summertime opera in America since 1932. The opera house in this quaint, former mining town near Denver is older still, built for music-loving Welsh and Cornish miners in the 1870s. With its charming trompe l’oeil decor and 756 seats – Beverly Sills sang Aida here – it offers further evidence that the economics of opera in America do not mandate gargantuan spaces.