As time slouches forward more and more of what was once popular - movies, music and novels, and everything - passes over into the land of the frankly incomprehensible. Is Charlie Chaplin still funny? A dwindling band of cinephiles say so, slightly more say Buster Keaton is, slightly more say the Marx Brothers still are... but what non-geek under the age of 40 will voluntarily watch a black and white movie from before the age of colour?
Jean Harlow was once, briefly, a screen goddess, but she seems like a caricature to us now, all beestung lips, white hair and strange lizardlike movements. Sometimes, like in the excellent Libelled Lady, she gives the impression of being great fun, but mostly, as in the insane melodrama China Seas she vamps around in the way only drag queens do now. Novels age better than movies but still, the vast majority of even great fiction over, let's say, 50 years old is only read because it's on a required reading list. Except Jane Austen, that is. She seems to be the exception that proves that rule.
It's possible, though - I bet there was a time - say, in the 1970s - when every other young woman didn't HAVE to read Jane Austen.
Popular music, being more technologically driven, has specific hurdles to overcome before contemporary ears can hear it - I think 1965 was the first year that records were made which actually sound modern, maybe something to do with the engineers finally getting a good drum sound. I have a naive hope that something like "I'm Down" or "I Fought the Law" or "Like a Rolling Stone" will last for centuries because they just sound so great but when the 50 year olds who currently control rock criticism die off, maybe not. It's a melancholy thought that however great an artist's work is it will in a few decades become impossible to hear, see or read without having to be festooned with explications and a blizzard of footnotes. Citizen Kane used to be the greatest movie ever, but not now. No one except us few bookgeeks reads Dickens for pleasure.
The opposite of this argument is the Robert Johnson Effect. This is where someone who was completely obscure in their own times is rediscovered by the geeks and then - very rarely - is parlayed by cunning marketing into being the cool style accessory du jour. Robert Johnson sold a few hundred 78s in the 1930s, but the cd in the 1990s sold over a million. Likewise The Buena Vista Social Club, and in recent years Nick Drake and Vashti Bunyan. All these odd cases are worth consideration and it's much easier to do this with music which takes much less time to buy and consume than books or movies.
All of our cherished art will become cartoons, all will grow a carapace of inscrutability and it will take dedicated cultural miners in the future to haul them all back to the crowded surface for the crowd to puzzle over and scratch their heads and wonder what kind of creatures liked them in the first place. Poor Jean - she'll never be sexy again.