Kaija Saariaho’s Innocence, which is currently enjoying its UK premiere at the Royal Opera House, is one opera where it does not pay to read the synopsis in advance. In most instances, the advantage of having some prior knowledge of what to look out for outweighs the disadvantage of any surprises being spoilt, but that is not the case here. This is because it is an opera in which we are constantly learning new things as the drama unfolds, with some of the revelations being so...