Stop, children, what's that sound?
Hmm, let's see: It's a little bit shrill and a tiny bit — okay, more than a tiny bit — out of tune. It's angry and sweet at the same time. And it's coming out of a girl who doesn't care if you like it or not.

Yes, that wail you'll be hearing tonight echoing onto the sidewalks at 34th St. and Eighth Ave. belongs to the most notorious anti-diva of the 21st century.

New York City — home of the 350,000-strong StopAshlee.com petition — is finally about to get its own concert-length dose of Ashlee Simpson's dubious songcraft, live and in person at the Hammerstein Ballroom.

After disastrous performances on "Saturday Night Live" and at the Orange Bowl, the younger of the Simpson siblings became the poster child for teenyboppers blessed with digitally enhanced talent.

But for the last month, the MTV icon has been out on the road, playing shows without the artificial sweeteners that made her palatable on "Autobiography," her triple-platinum debut album.

So far, reviews of her shows have been mixed. The Seattle Times said "there was no lip-synching" at her show there last month. But the ­paper also noted that "there was no singing, either."

In Minneapolis last week, the Star Tribune lauded her for perky covers of Blondie, the Pretenders and Madonna. But overall, "there was no subtlety or sense of nuance to her singing."

For once, Simpson has been limiting her exposure, playing relatively short, hour-long sets that include a few breaks and a brief showcase of acoustic songs. And any criticism by reviewers has been drowned out by the adoring shrieks of her largely female teen and preteen fans.

Perhaps the T-shirts for sale at Simpson's concerts say it best.

Spelling her name with the "A" that was a punk-era symbol for anarchy, the shirts coopt the spirit of devil-may-care underground music and brand it into a consumer-friendly accessory.

Simpson herself, after all, is a well-crafted product with only one serious glitch — it doesn't seem as if she can actually do the one thing she was created for. But at a time when the White House crafts fake news reports and viewers look to Jon Stewart's "fake news" show for the truth, Ashlee Simpson may simply be the ultimate expression of our times.