What makes something that's classic, timeless? The two, in terms of creativity, sound as if they mean the same thing. But I think they're a world away from each other - as I am from my daughter.
Aged 15, she's studying American civil rights for history (her Martin Luther essays are far more interesting than my 16th century ones were) and enthusiastically told me last night that they'd spent this week's lesson debating the influence Bob Dylan had on politics, especially with songs such as Blowin' In The Wind. 'It's such a classic song, dad.'
Coincidentally, I was just getting ready to leave for the Royal Albert Hall to watch Dylan's return to a venue that once marked the end of his most extraordinarily creative and self-destructive period, that began with that wind and ended in a tangle of Blonde On Blonde boos. This time the 'wild mercury' had been replaced by wistful bluegrass, tender piano and blues-laden growls.
And for his encore, a hushed arena listened intently to an old man asking how many times we'd have to walk down a road before we can call ourselves men.
The song was both familiar and unrecognisable, the message was the same but somehow different, the meaning as out-of-reach as it was 51 years ago.
Fifty one years ago, Blowin' In The Wind was adopted as some kind of clarion call for an energetic, shackled and questioning youth to stop relying on their elders for answers, to open their eyes to the unfairness around them, to strive to find a different path at the end of which truths would miraculously materialise.
And last night, to a 40-something dad whose scars now define him more than youthful urges once did, I realised that the call to arms had turned into a lament.
'How many years can some people exist before they're allowed to be free?' Much longer than I (he) ever imagined. 'How many times must the cannonballs fly before they're forever banned?' Are you kidding? 'How many times can a man look up before he can see the sky.' I'm not sure that I'm really any closer to be honest than when I first heard it sung 35 years ago.
And that's what makes something classic, timeless. That it changes, yet somehow grows deeper. It's the same construction of words and images but it means something entirely different - just as apt but with a significance that it never had when it was first created.
Once, the song was defiant, questioning, naïve and hopeful. Now it's sad, thoughtful, romantic yet still hopeful. Or maybe that's just me.
Truly great works of art change and become more meaningful experiences as they age. Thus post-war novels like 1984 and A Clockwork Orange, or cinema that reflected anti-establishment paranoia - all fuel for the Dylan's Sixties Generation - are now timeless works because they continue to reflect society in a way their creators never envisaged.
I couldn't wait to tell my daughter over breakfast about last night's gig and how I fell back in love with a song that she's just discovered and fallen in love with for herself. That perhaps it would uniquely bind us.
So I told her.
'What? Oh that song. Yeah it's OK I guess. But that was yesterday Dad. I want to get the new One Direction album. It's a classic.'