"Great cities deserve great markets," recites Nicky Uy, the laid-back, on-site manager for the Food Trust, the market's nonprofit sponsor.
And so as farmers displayed cascades of heirloom tomatoes and polished onions, and the scent of toasting corn tortillas rose from Los Taquitos de Puebla portable griddle, there were palpable resonances of San Francisco's Ferry Plaza farmers' market, and (as chef Marcie Turney and her partner, Valerie Safran, shopped for greens for the Head House Square Farmers' Market Salad they're running as a weekly special at Lolita) of the Union Square greenmarket in Manhattan, which inspires menus at cafes on its flank.
You hear boom-time talk: How about twice as many farmers next summer, covering the cobblestones outside with a field of pavilion tents? Why stop at the end of fall? What about selling Christmas trees in December?
Wild Flour Bakery, the wholesale bakery that makes exotic flatbreads, pastries and the challah rolls for Rouge's prize-winning burgers, has been so stunned by the bear hug for its first venture into retailing that it's re-examining its business plan.
Is it time, co-owner Laura Yaghoobian wonders, to invest in a retail storefront?
Philadelphia, of course, has the Reading Terminal Market, a century-old youngster compared with the Head House space, which dates to 1745. But Reading market has strayed from its role as a farm-fresh provisioner, and, as a metaphor, is now embroiled in an unseemly public brawl over the lease for a tourist-stop cheesesteak stand.
So perhaps Head House is back from the grave to re-teach a lesson. There is still value in the city's original equipment (streets such as Second bulging here and there to accommodate sociable commerce) and its functional impulses (the slate-roofed National Historic Landmark shed is colonnaded and understated, straightforward and democratic).
"This was a people's market," says Ken Finkel, who has written widely on the subject, "the public square of the day."
Indeed, a German visitor in 1818 was startled to see even well-heeled gentlemen toting home baskets of butter and eggs, a job for servants back in Frankfurt.
No one can predict what the future holds for this prodigal echo. But things are off to a robust start: At roughly 28 vendors, Head House is the city's instant big mama, more than double the size of the Clark Park market, its nearest runner-up.
About 1,500 shoppers have been showing up during market hours, 10 a.m. to 2 p.m. on Sundays.
Nearly half are from the surrounding Society Hill, Old City and Queen Village neighborhoods. But, untypically, visitors have come from 15 zip codes.
The farmers have fewer wrinkles: As agriculture has grayed, the average age of farmers nationally is 58. Here, about a quarter of the vendors are under 35.
The Sunday-morning time slot was originally chosen so as not to compete with the Reading Market (which has begun, with some success, opening on Sundays, too). But it has turned out to be a profitable choice: Sunday is now America's biggest grocery shopping day.
Food Trust director Yael Lehmann says farmers have been recruited in the past with assurances that they could take home $1,000 on a peak-season day. At Head House, the stronger vendors have already done double that; one had a $2,500 day.
Sixteen of the vendors are new to town markets. Griggstown (N.J.) Quail Farm has made the jump across the Delaware: Its juicy chicken-apple sausage and frozen chicken pies are all the buzz. There's Birchrun Hill Farm, the upstart Chester County cheese-maker. And Wild Flour, the first-time retailer.
So it is natural as you stroll beneath the hanging lanterns, and hear hoofbeats knocking across the cobblestones, for a question to well up: What the heck took so long?
You can finger the usual suspects - failures of imagination and a casual neglect of historical treasure. But even Bernice Hamel, who heads up the Head House Conservancy, which rescued the place from disrepair 20 years ago, was stunned at the pent-up hunger for a market: "We were hugging each other; kissing each other," she said, as the opening-day crowds surged.
In Rittenhouse Square, the locals were ambivalent about their now-limping weekend market. No such restraint in the bosom of Society Hill.
They show up unshaven, kids in tow, in "Provence" T-shirts, reusable shopping bags from Whole Foods and Trader Joe's at the ready, encountering at one stand pasture-raised, free-range eggs for $5 a dozen from Walnutport, Pa., north of Allentown.
But veterans of organic and artisanal markets have no complaints about prices: Larry Becker, the Old City art dealer, was happy to fork over $3 for a bag of springy, organic greens that his wife, Heidi, later topped with stir-fried Chinese long beans from Queens Farm.
Walking the brick pavement under the gently arched, freshly resealed ceiling, you can conjure the Head House of yore: It was the "New Market" then, a spur off the main shambles (as the sheds were called) that lined colonial Market Street.
Tuesdays and Fridays were the market days, the farm wagons pulling up outside the brick piers, shoppers grazing under cover. It wasn't uncommon to find fresh raccoon or possum, bear bacon or turtle.
But the standard fare sounds strikingly similar to the Head House's current offerings - vegetables and fruit, fresh eggs and chicken, various sausages, and meat and apple pies (two of Griggstown's specialities).
Last Sunday, you could watch the carver from Los Taquitos de Puebla, the Mexican stand, take his blade to the cone of pork sweating on a vertical, rotating spit.
Spiked on the spit, trickling its juice onto the meat below, was a sunny pineapple, once the symbol in Philadelphia of bountiful trade with the West Indies, and to this day, an icon of greeting and welcome.
Talk about a sweet and undulled echo.
Head House Farmers' Market Second and Lombard Streets, Sundays, 10 a.m. to 2 p.m., www.thefoodtrust.org
Contact columnist Rick Nichols at 215-854-2715 or email@example.com. To view previous columns and a video about Queens Farm, a vender at the market, go to http://go.philly.com/ricknichols