(Regarding the second edition, 2021). Good biographies on musicians tend to be very rare, especially ones on organists. I did not read the first edition, but I was quite enthousiastic about the appearance of this 2021 expanded reprint. Despite all the good efforts, I have to say, regretfully, that I do not like this biography at all.
My main point of critisism is that it lacks a critical evaluation of the person Marcel Dupré. It is obvious that Michael Murray is a huge fan of Dupré, unfortunately, that blurred his objectivity. Almost everything is seen from Dupré's perspective, and hardly a trace of critisism can be found. Murray does not mention Dupré's dark side, and he f.e. neglects the conflict with Jeanne Demessieux. He 'discusses' the relationship with Louis Vierne very briefly, and he could be way more elaborate regarding the matter.
A long story short, this book lacks a critical evaluation, and, thefore, does not present a complete picture of this great organist.