My head was spinning every time I put this book down. Spinning with shock, compassion, confusion, inspiration, but mostly anger. Anger that a person with so much to say does so with such levels of unchecked inelegance and confusion; anger that someone with so much appetite for change and renewal has missed countless opportunities to practise what he so tirelessly and loudly preaches.

In less than a decade, James Rhodes has gone from issuing his debut recording as a pianist to campaigning for music education in his own prime-time television slot. He is a vital and significant presence who is lambasting our industry into positive change through words and actions. I make no apology, as a writer for a magazine Rhodes describes in his book as ‘somewhere between peanut butter and Andrex moist wipes on the scale of worldly importance’, for believing many of his ideas both long overdue and bang on the money. I don’t find his cosy vicarage jokes funny even when they’re disguised in the angry, profanity-laden language of one who’s experienced the world at its absolute worst. But it’s a compliment to Rhodes that I doubt he’d mind me saying so.

Still, Instrumental is…well, what is it? It’s a mess. That might be entirely necessary and of secondary importance given the huge issues Rhodes is dealing with (child rape, addiction, the overwhelming challenges of everyday life after experiencing either of those, and the increasing estrangement of the great music we all claim to love). But it’s true. The book lurches from autobiography to rant to careers handbook for professionals to entry-level composer guide to industry manifesto to critique of mental health care to rambling diary to tub-thumping lecture on how to conduct a relationship and more besides. It’s littered with half-truths (‘Glenn Gould poured boiling water over his hands and forearms before playing’) and is exhausting in its haranguing, I‑speak-the-truth tone.

Rhodes directs his book at those outside the classical music world yet kicks phrases like ‘existing conventions around tonality’, ‘active repertory’ and ‘étude’ around with no explanation of their meaning. He talks constantly of composers ‘changing the world’ but stops short of explaining, even in the simplest terms, how they did so. He bemoans the tired language and convention of the industry yet pretentiously refers to himself throughout as a ‘concert pianist’ (isn’t he just a ‘pianist’?). He contradicts himself endlessly (‘everything about classical music…is almost totally devoid of any redeeming features’; ‘classical music needs to stop apologising for itself’) and his inconsistent and incalculable financial references are irritatingly gauche (for the record, owning a flat with only one bathroom in Maida Vale isn’t the definition of failure; for most 38-year-olds it’s actually out of reach). He relentlessly attacks celebrity culture and then casts composers as ‘rock stars’ and lingers cringeworthily on his friendship with Stephen Fry; we learn nothing of Rhodes’s ‘best friend, best man, best everything’ – a bloke called Matthew who is pretty much consigned to the acknowledgements page.

And yet, what a life Rhodes has had – what a journey he has been on, and how astonishingly honest he is when it comes to the abhorrent crime and tragedy of child rape (he understandably detests the word ‘abuse’). His descriptions of what he endured from the age of five are graphic and horrifying, and his analysis of how those events have in some sense come to define him both physically and mentally are real, clear, cutting (literally) and devastating. You can’t help but fume and weep for him – with him; you can’t help but naively will the erasing of the past and the glimpsing of a James Rhodes who never had these horrors to contend with and doesn’t still.

Those horrors are real and Rhodes deals with them astonishingly. But problems arise when music is seemingly crowbarred back into the narrative. ‘Music quite literally saved my life,’ Rhodes posits in his introduction. But music disappears for pages on end, fails to do the business when required and is never acutely linked to a process of psychological strengthening. Instead, two self-help books initiated Rhodes’s most significant recovery process and then, or so the ensuing text suggests, he saved himself through mental strength wrought from love for his son and his girlfriend. That allowed him to pursue his career in music, not the other way around.

Rhodes’s fans might not care about these inconsistencies and I hope his book enlightens them in the ways it has the potential to. But as with Rhodes’s arguments about crossover music, he should have credited his readers with a little more intelligence and curiosity. He should have offered them more nuance, more structure, more consistency, more musical exploration, less meaningless hyperbole and less cliché, whether they’d appreciate it or not.

Details Canongate, HB, 275pp, £14.99. ISBN 978-1-78211-338-6. 'Instrumental' on Amazon

This review appears in the August 2015 issue of Gramophone – on sale now. Subscribe to Gramophone