I think the only thing that made me finish this book was that I wanted to be able to write a full review here on Amazon.
Others have already commented on the incessant and appalling attempts at humour throughout - often a seemingly interesting and relevant comment or fact quickly becomes yet another feeble setup for a dodgy pun or surreal gag.
Bearing in mind this book is clearly aimed at those of us who aren't experts in the field of classical music, it's very frustrating to find there's almost nothing on terminology and the structure of classical music, apart from a brief bit on concertos. If you want to know how a symphony differs from a mass, or what an overture actually is, or a sonata, or a tenor, or soprano, you will need to look elsewhere.
Most of the composers themselves are only briefly discussed or mentioned, with the majority of the text given over to describing the author's own opinion of his favourite pieces of music, the rubbish jokes, or lists of contemporary history that's usually got nothing to do with the music.
There are no pictures such as portraits of the composers, there's no index or glossary, nor advise on further reading or even a bibliography.
Having read a couple of Stephen Fry's other books it is almost immediately clear that he is not the main writer (if at all), and the various references within the text suggesting otherwise are almost insulting.
I'm thrilled to have finally finished it so I can now read something (anything) else, and feel the only thing I have learnt from it is to be very cautious of books that say "as told to ..." on the cover.