London is lucky to have heard Joyce DiDonato at the height of her powers in two consecutive seasons. The American mezzo has arguably done less well out of the arrangement, however, finding herself at the centre of two disappointing new productions. Last year it was Rossini’s La Donna del Lago, an intractable non-drama which John Fulljames’s staging (sponsored by Harris Tweed) turned into an unconvincing treatise on constructions of Scottish nationalism.