Encouraged by Kevin S, I have been giving Fibich's opera another listen. I am not convinced that it's a great work (there's not enough melodically memorable material in it to my way of thinking). However, the 10-minute Funeral March in Act 3 is an absolutely stunning and original piece of writing - much the most arresting music in the entire opera. And the classic Supraphon recording from 1975 features some marvellous singing, particularly from the great Slovakian lyric soprano, Gabriela Beňačková (b.1947) - only 28 at the time of the recording. So there is pleasure to be had merely from listening to fine singers in the many beautiful passages of the opera.