It doesn't matter. As one who lived through it, I'm amazed that anyone would want to revisit that period. Yet here we go again.

Unlike the swing thing, still lindy hoppin' along, and the "Grease"-inspired '50s craze that raged throughout the '70s themselves, this wave of nostalgia seems to be less an homage to an idealized past era by people who never saw it than a recollection by the aging population who did.

Although I'm told that groups like the Afrodisiacs are attracting the younger set to re-enact the -- ugh -- disco scene at clubs, most of what I'm seeing at revivals of 30-year-old entertainment is a lot of graying heads.

Peter, Paul and Mary, who began in the '60s and disbanded in 1970, but who probably were at the height of their fame when they reunited in 1978, appeared at Symphony Center last month. A throaty Mary Travers strained for the notes and a balding Noel Paul Stookey exulted at performing in an indoor setting (vs. that more traditional local venue of aging pop stars, Ravinia), and the audience applauded and laughed and sang along, reveling in old favorites like "Puff the Magic Dragon," "Lemon Tree" and "Blowin' in the Wind."

As far as I could tell, anyone under 30 at that show came with his mother.

The Who's rock opera, "Tommy," is 30 years old this year, and we get a week of its 1993 Broadway show here in homage. The traveling show hadn't yet opened when we went to press with this issue, so I can't tell you who is going to see it. Yet I find it hard to imagine "Tommy" has much to say to younger people. Less, even than "Blowin' in the Wind."

The story tells of a young boy who becomes traumatically deaf, dumb and blind after witnessing his cuckolded father shoot his mother's lover, and who is later sexually abused and tormented by other relatives before being elevated into a celebrity through his talent at pinball. That the album's centerpiece tune, "Pinball Wizard," was an anthem of its era, just goes to show how painful that decade was.

Consider also that among the era's blockbuster films were the disaster flicks of Irwin Allen: "The Towering Inferno," "The Poseidon Adventure," etc. These are also being revisited here in The Free Associates' current themed-improv show, "That Sinking Feeling." Film buffs come in all age groups so the audience there was a little younger. But not much.

What gives? Wasn't all that angst enough the first time around?

"That Sinking Feeling: The Master of Disaster Remastered" continues through June 12 at the Ivanhoe Theater, 750 W. Wellington St., Chicago. Tickets are $10 to $12. Call (773) 975-7171.