The bulge in the population represented by post-World War II baby boomers doesn’t just affect Social Security futures. It also affects rock ‘n’ roll. This was the rock generation, after all, grew up and ate and breathed the stuff. And when we grew up we were going to just keep on rockin, right?

Well, not so much. Rather than keeping up with the rockers, the boomers have kept their hand in music mostly by buying their old music over and over.

When there’s no new music to be had from their favorite artists (who have been their favorite artists for decades), the only thing left to do is buy the old stuff one more time.

I already avoided buying the remastered “Exile on Main Street” last year (though I picked up the rarities disc). I already had at least three different remastered versions already. How many times are you going to repave this street? How long will it retain its original grit?

The Boss has no new album to sell, but he has unreleased tracks from one period of his life, before “Darkness on the Edge of Town” was released. So that’s out now too as new product. (Some of it has added horns and vocals, as did the Stones rarities – as if acts are afraid of really releasing their sketchbooks unless they finish the entire drawing, years later).

The Beatles released all their stuff remastered on stereo and mono last year, this year with an even bigger promotional push, The Beatles stuff is finally on iTunes. Who exactly didn’t have these things before? Or are people just buying them anew rather than burning their discs?

Given the mono route, there’s a whole box of remastered Bob Dylan on mono. There’s a new Michael Jackson out, but it’s all very old Michael Jackson, with added tracks and vocals (Akon, poor kid, thinks he’s singing with MJ instead of a disembodied recording).

Jackson’s onetime duet partner Paul McCartney is quite visible this season, but he’s got no new product but an enhanced “deluxe” “Band on the Run” to peddle. I think I have an earlier “deluxe version” of that one too.

The 30th anniversary of John Lennon’s death this month brought with it the requisite number of reissues, prime among them an unusual “Stripped Down” version of his final album “Double Fantasy,” in which the Phil Spector gloss Lennon so desired has been scraped off. It makes a few of the songs sound more interesting, but it reminds you all too quickly that half the album is from Yoko.

The “Stripped Down” album is not included in the 11 disc, $190 Lennon “Signature Box” that features eight solo albums and a short CD of rarities.

Those who refuse to play their old albums are condemned to buy them all again.

Nobody expects new stuff from Lennon, Jackson but come on, Bruce, Paul, the Stones, you can try to put out some new stuff sometime. Even on an EP if you have to.