You can tell you are getting older when people start trying to sell your youth back to you. Most folks are aware when this happens, and buy anyway.

And sometimes what they're selling is not exactly what they say it is.

But, as was the case with a doo-wop concert here Saturday night, audiences seem to like it anyway.

Groups calling themselves Cornell Gunter's Coasters, The Marvellettes and The Platters played to an almost full house at the Strand-Capital Performing Arts Center.

Baby boomers and even pre-baby boomers — among them a busload from a local retirement community and a gaggle of Red Hats — were entertained by passable versions of the '50s and '60s hits they grew up with.

They reminisced, they swayed, gave standing ovations, even danced in the aisles a little.

Trouble is, none of the acts contained anyone who sang the vintage hits of those groups.

In early 2006, Pennsylvania was the first state to make it a crime for any such group to perform without an original recording member, a federally registered copyright, or under a billing that clearly calls the show a tribute or review.

The Strand show was called a "Celebration of Doo-Wop, featuring the music of the Coasters, Platters and Marvelletes."

Was Saturday night's performance a criminal act? Evidently, neither the state's attorney general's office nor the county prosecutors headquartered across the street thought so.

All three musical groups are the product of New York-based promoter Larry Marshak. The real doo-wop stars, and they are a sadly shrinking few, say they are routinely undercut by these groups.

Marshak has been putting similar deceptively billed groups on the road since the 1970s.

The lineup for Saturday's show had previously included a Marshak Drifters group, but a federal court ruling in September called the whole thing "an elaborate shell game."

Ticketholders were told via e-mail about the change three weeks ago. They were not told why.

Drifter Charlie Thomas, who sang on hits like "On Broadway," "Up On The Roof" and "There Goes My Baby," runs his current touring efforts through management based in York, and was a York resident himself for many years.

Thanks to the courts, there were no fake Drifters performing on his home turf.

For most patrons, though, the concert brought back the carefree days of their teenage or young adult years — even if it included some unbalanced harmonies, competent yet unspirited musical backing, oversinging and mellismatic flourishes galore.

Most of the stand-ins onstage were not even born when the songs they sang were hits, but most concertgoers interviewed were aware of that going in and didn't see it as a problem.

For Lee Bainbridge of York, the music of the groups represented is what counts.

"This kind of music is responsible for bringing a lot of people together, and keeping them together still. The songs are immortal."

"We didn't expect to see the originals," said Carolyn Hood of New Freedom.

Peggy Mayes, of Baltimore, didn't seem to mind, either.

"They were older than us even way back then. They were great. They sounded just like the originals."

But can anything really compare to the vinyl played on mom and dad's hi-fi?

For a true trip back in time, check out some of the old television appearances by the real groups on youtube.com. (Consider anything in color to be suspect.)

As a matter of comparison, the Strand hosts Dark Star Orchestra in December, an act that lets concertgoers "relive the Grateful Dead."

Notice the difference. They don't call themselves the Grateful Dead. Why not? Because Dead fans wouldn't stand for it.

Perhaps the children of the 1950s are more forgiving.

Nostalgia is a powerful thing indeed.