It's doubtful if the drinking song from La Traviata has ever been sung to the clinking of teacups, but the Cheltenham Music Festival's Fine Tea Tasting and Opera event was something of a first in every respect. Not many concerts of operatic excerpts are preceded by a short film about the processing of leaves from Camellia sinensis assamica. But Mackwoods, whose single-estate tea leaves from Sri Lanka were being infused here, were out to educate us in the art of tea-drinking. ...