The great American conductor and sketch comedian André Previn made an excellent point in the 1970s about the thankfully passing fashion of prog rock bands like Emerson, Lake and Palmer doing their own interpretations of classical favourites. If you went into the Louvre and drew a moustache on the Mona Lisa, he observed, you’d be rightfully arrested. So why, he argued, should musicians get away unscathed with mistreating the works of past greats?

Previn’s proposition sprang to mind last night during Bob Dylan’s concert at Vancouver’s Rogers Arena, with one notable addendum. Is it acceptable to reinterpret some of the best songs of the 20th Century if you’re the artist that created them to begin with?

That’s the dilemma of the 2012 Bob Dylan live experience.

On one hand, this was Dylan, arguably the greatest American songwriter of his or any other generation. He’s earned the right to do exactly what he likes.

On the other hand, these are songs he’s gifted to the world and people love. They deserve to be treated with respect.

It goes without saying that the nasal snap that ripped through the complacency of the early 60s’ airwaves has long been replaced by a throaty rasp. That’s fair enough. Despite refusing all requests from professional concert photographers (unlike Justin Bieber, who 48 hours earlier welcomed cameras into Rogers Arena but declined requests from reviewers) Dylan wore his 71 years well. Dressed in all black aside from his permanently fixed white hat, he patrolled the stage like an aging gunslinger, shifting between organ, piano and harmonica (but never guitar).

“Things Have Changed” and “High Water (For Charley Patton)” were highlights, full of restless energy and vocal performances that, although completely incomprehensible, delivered a noticeable degree of passion. Dylan’s newer material all sounded pretty robust. The issues lay with the way he was manhandling the classics.

“Tangled Up In Blue” was the first victim, bestowed with a new melody and a guitar riff plundered directly from Elvis’ “Suspicious Minds”, its radical lyrics possibly rewritten to “oobba-nu-wonna-mmm-th-mooOOO.”

“Desolation Row,” was unrecognizable apart for its unique guitar strum at the end of every verse. “Highway 61” maintained a few shades of its original vibrancy and “Ballad of a Thin Man” retained its menacing sonic palette in everything aside from Dylan’s barked stabs at singing.

To his credit, Dylan was delivering the hits. He was also smashing them apart when they arrived. “Like A Rolling Stone” won the biggest cheer of the night before it became apparent that this rendition would be impossible to sing along with.

“Thank you friends,” Dylan smiled at the song’s end, his only words to the crowd all night. Although he may have been talking to his band, who he introduced with hilarious inarticulateness. “On lead guitar, Migwaaaan Hmmuulleunch.”

Plenty of fans were heading home early, missing out on a rocking version of “All Along The Watchtower.” The encore, an impotent jazz-blues “Blowing In The Wind” didn’t lure anyone back to their seats.

The biggest cheer of the entire night came for supporting act Mark Knopfler, whose pleasant combination of big band folk-rock and blues produced a standing ovation. The irony of the night was that while Dylan delivered a torrent of hits, Knopfler failed to delve into his Dire Straits back catalogue even once. No stranger to croaky vocals himself, Knopfler never reached for a note he couldn’t hit or mumbled through a line impossible to decipher.

Of course, the difference is that Knopfler is a seasoned professional and Dylan is a genius. Leonardo Da Vinci was a genius too. Smart enough to know that the Mona Lisa looked better without a moustache.