As a young and smart-alecky music fan, I used to very much like quoting a maxim attributed to Bob Dylan, about Smokey Robinson being the greatest living American poet.

I liked this claim, because there seemed to me to be so much in it - about the spurious distinctions drawn between high and low culture, about the rightful or denied or debatable place of pop music within literature and about the dearth of black creators permitted into the canon of "serious" literature, as well as about what a bloody fantastic poet Smokey Robinson is.

Now it's Dylan himself who has been granted the official status of a poet for the ages, with the surprising and contentious conferral of a Nobel Prize for Literature.

To some, this is appropriate acknowledgement of the vast, various and immeasurably influential wordsmithery of a venerable bard. To others, it's all wrong: at best a peculiar category error, at worst a slap in the face to those who've given their lives and careers to wrangling words in their pure form. And to still others, it smacks of deliberate controversy-baiting: a publicity stunt for a dusty, elitist gong.

Smokey Robinson's thoughts on the matter are thus far unknown.

All sides of the stooshie might be persuaded to agree, however, that this development adds yet another layer of mythology to an artist already famed and derided for his mutable public image. In his film I'm Not There, Todd Haynes made literal the multiplicity of Bobs, portraying him as a black hobo child prone to self-mythologisation; a self-loathing teen idol movie star; French symbolist poet Arthur Rimbaud, one of his acknowledged inspirations; his druggy, sardonic 1960s celebrity incarnation, albeit by another name and in the female body of Cate Blanchett; an earnest born-again Christian preacher; and grizzled American outlaw Billy the Kid.

Perhaps another chapter could now be added on, with Dylan re-envisioned as a grizzled professor pontificating about literature in a book-lined study. Because what's fascinating about the reaction to Dylan the Nobel laureate is the extent to which it reinforces the point made by Haynes' film: that Dylan, in his refusal to be stably categorised, in his weird mix of outsider orneriness and straightforward mainstream celebrity, and in the unsettling insincerity he projects, continues to draw out all sorts of nervousness and insecurity about art and identity.

He has a unique power to unsettle people, because his habit of confounding whatever idea they have of him - the protest singer who finally didn't care much about protest; the Jew who became a born-again Christian; the megastar about whom we somehow know close to nothing - wrongfoots them, makes them feel silly, seems UNGRATEFUL.

Now, not content with keeping everyone troubled about who he is, he's thrown all up in the air what literature is. For if Dylan - yes, technically a poet in that he has published poetry, but clearly in his most celebrated output a singer-songwriter and performer as well - can be recognised as one of the very best at doing things with words, then why not a filmmaker, whose output while it might take in other elements most certainly depends on words arranged in inventive, meaningful and beautiful order? (Why not Todd Haynes?) And why only fiction filmmakers, given that non-fiction writers get given it - including Svetlana Alexievich in 2015 and Winston Churchill in 1953? (Werner Herzog, step up.)

Come to that, if we are prepared to recognise - as surely Dylan's award does - that performance, delivery, even persona play into what it takes to be a great literary force, then why exclude forms of communication that don't rely on language at all? Quite a lot of Dylan's work prioritises the form of words - their musical effect, and the way his delivery distorts them - over what they actually mean; as a musician, his words are in part an instrument. So does awarding him indicate a recognition by a committee that has tended towards a fairly conventional take on what literature is that language and meaning can occupy separate spaces? Or did they already set that in stone when they awarded Beckett in 1969? In any case, why not, given this precedent, a musician who doesn't use words at all? They also communicate ideas. Why not a dancer?

Perhaps one thing alone is certain: old man of the establishment he may be, but when you throw Dylan into the mix, everything still gets antsy and confusing.

Objections to this award have ranged from the simply philistine (the popular can't be clever; poetry ceases to be such if and when it happens to be set to music) to the straightforward (er, why's there no Nobel Prize for music?) to the crossly political (Albert Nobel patented dynamite! He's a MASTER OF WAR, Bob! You're not supposed to like those!). Then there's the slightly sour-grapesy but hard-to-challenge argument that someone who has for most of his long career been massively lauded and flung every possible garland in his field doesn't really need yet another one from somewhere else, especially when hails from that hardly-underrepresented category, the White English-Speaking Male.

Me personally, I approve of the treatment of (to quote a sub-heading on an anthology of works by the rock critic Lester Bangs) "rock'n'roll as literature, literature as rock'n'roll". I might have been more behind Smokey Robinson as a choice. Although, that quote I started with, about Robinson being the greatest living American poet? Typical slippery Dylan: it turns out he probably didn't even say it. Al Abrams, who was head of PR for Motown Records in the 1960s, has claimed that he made it up, based on the fact that he knew Dylan liked Robinson's lyrics and that so much hokum circulated about him that he probably wouldn't challenge it. People continue to circulate it - like I just did - because it sounds good, and fits an image.

And maybe that's what the Dylan Nobel moment tells us: that the capacity required to make oneself into an endless repository of rumours, controversies and half-truths perhaps commands recognition as its own sui generis brand of storytelling. Voice of a generation he might never have wanted to be; model for a couple of generations preoccupied by celebrity and self-reinvention he undeniably is.

Hannah McGill is a writer, critic and broadcaster based in Edinburgh. She writes for Scotland on Sunday, Sight and Sound, The Independent and The Times among other outlets. From 2006 to 2010 she was the artistic director of the Edinburgh International Film Festival.