This book is generally spoken of on castrati mailing lists, message boards, etc. in glowing terms. It's the book everyone's supposed to read, the essential reference guide, the book Patrick Barbier's
The World of the Castrati failed to supplant.
Well,
I agree that Barbier's book could be better, but at least he cites his sources! Heriot just doesn't bother. At all. If you're lucky, he'll name an author, or maybe even a publication. But there's no need to assume that that author / publication will be listed in his bibliography. Half the time it isn't. As for specific page-references - forget it! Footnotes, as far as Heriot is concerned, are for crow-barring in tangentially-related stories he couldn't find a good place for in his main text.
There's also very little attempt at any meaningful analysis of the subject-matter. The text is descriptive, with the emphasis on anecdotes - in essence, what Heriot wants to do is tell us all the great stories about duels, diva-esque behaviour, sexual antics and partisanship in the theatre that he can get his hands on. That's OK so far as it goes, but it makes the lack of references all the more frustrating. He's obviously drawing on a wealth of amazing primary material to do all this, and he quotes quite a lot of it at length. But as a reader, you're never sure how much authority he has for his more generalising statements, and you'd be hard-pressed to follow any of the material up on your own account. Personally, I'd much rather just read a straightforward source-book.
Add to that the fact that what analysis there is is dated and simplistic. The castrati themselves get away more-or-less OK, but women get a very rough deal indeed. They are portrayed consistently either as air-headed, hot-tempered or simply naturally less able and professional singers than their male counterparts. And where I was in a position to compare his analyses of particular events with those of others - e.g. on the formation of the Opera of the Nobility in 1733, or the story of
Sorlisi's marriage - I'm afraid I found them sadly lacking.
I don't regret reading it, because it is an easy reference point for the basic stories of most of the best-known castrati, it does at least give clues as to where one might find out more, even if not proper pointers, and hell - if you're in the mood for colourful anecdotes, it's a great read. But it really doesn't deserve its general reputation.