So much of life fits into a structure and forces you to think a certain way, or not to think at all. The world is so highly regulated that there are too many boxes in it, where everyone does everything exactly the same.

Society demands that we all drive in one direction on each side of the highway, and the government wants you to fill out you tax return precisely according to the directions, and you should show up on time for work or school or your doctor appointment. That's okay, though. We have to have rules or we'll all be running into each other.

The struggle is to keep yourself from letting the rules make you a gray flannel clone with nothing new to give the world. We still have art, with more flexible parameters and less stringent limits. Creating art expresses who you are, outside the rules of others.

Appreciating art is a creative experience, too. Letting yourself get lost in a book or a painting or a piece of music is liberating, and at least as necessary to survival as obeying traffic laws. That's why restrictive governments consider art to be a subversive influence. They want to make laws and rules for art and culture and keep it in a box, along with the artist.

But you know what? Popular culture will almost always head in the direction of more freedom. That's why we had Benny Goodman in the 1930s, and Elvis Presley in the 1950s, punk and funk in the 1970s and 1980s, and Eminem today.

This doesn't explain disco, but then, what does? No progression is smooth, without its potholes and pitfalls. Boy bands, anyone? (Are they really "bands" if they just sing and dance? They're more like Dean Martin's Golddiggers, or the lovely Lennon Sisters.)

But every time ... okay, almost every time what's popular becomes predictable, something new comes along to blow it away. Or at least to breathe new life into it. Only the innovative and exhilarating works of artists creating on the razor's edge are likely to stand up from one generation to the next, and beyond. Hence, Goodman. And Presley. Eminem? We'll see.

Obviously, I was watching Jazz on PBS again last night and learned some things about my parents' era that were new to me. It's not just the music that keeps me coming back to this program, but the history as well.

Critics have carped that the show is too comprehensive, or not inclusive enough, with too many words and not enough music, or too concentrated on the first half of the twentieth century. That part's okay with me, since I lived through the second half and even remember bits of it.

I knew nothing, really, about the swing era, except for some of the music. I knew Louis Armstrong was an important figure in musical history, but I didn't know he was so important, or why.

And I have a lot more respect for Benny Goodman after last night's episode. (They sure made short work out of dismissing Glenn Miller, though, didn't they? And where the heck was Frank Sinatra, besides one mention and one still picture? Ah, but I guess we're all critics at heart.)

I had to put on a Billie Holiday CD after the program was over. That voice. That phrasing. Same things I admire about Sinatra. That's what jazz gave us, the interpretation of melody by the individual artist. The only music I don't listen to is the kind with no melody. There's way too much of that today, but that's what progress does. It leaves the old ways (and the old folks) behind.