Silver hairs are bound to bristle that first moment when the old clientele crosses the Sansom Street threshold of their beloved Oyster House again. I could literally hear a curmudgeonly "grrrr . . ." rumble from my companion as he surveyed the drastic changes that had been visited upon his old half-shell haunt.

Gone is the clubby darkness of varnished wood, creaky chairs, and cloistered back rooms. The space is open, bright, noisy, and modern now – a gleam of subway tile, glass partitions, marine-gray wainscoting, and whitewashed brick that twinkles with a spray of antique oyster plates. The once-central front bar has been pushed aside, making way for a larger, lively lounge. A bigger raw bar, meanwhile, traces the heart of the room with a smooth marble-and-glass-trimmed counter.

And it is from a seat there - with access to O.T.C. crackers, horseradish, and a close-up of master shuckers Ameen Lawrence and Cornell Rhodes plying their shell-craft - that my friend finally relaxed. He even cracked a smile when a gorgeous platter of bivalves arrived, each meticulously shucked and glistening in a pool of its own liquor.

The Chincoteagues awakened our palates with a nice salty pop. The milder West Coast Royal Miyagis weren't as firm, but delivered a creamy, cucumber savor. The Connecticut Mystics from Fishers Island Sound had a mellow saltiness that lingered with sweet tidal warmth. The tender Wellfleets were like gulps of Cape Cod Bay. But it was the little Pemaquids that made us cheer: Those small but mighty Mainers washed our taste buds with a brisk oceanic rinse.

With just a few slurps, all was right with the world. After a hollow year in which Center City nearly lost all its classic fish houses - for the first time in more than a century! - the Oyster House's rebirth is a welcome reaffirmation of our roots, even if this new edition is strikingly different from its older self.

It is in so many ways a big improvement over the tottering relic it had become before its previous owner lost it to bankruptcy. Back now with its original caretakers, the Mink family, third-generation owner Sam Mink, 33, has recast it boldly into modern form, from decor changes to draw energy and a youthful crowd, to a bright young staff that knows its oysters, a quality cocktail bar, beer and wine list, and a kitchen that updates the classics with seasonal ingredients and a lighter touch.

That lightening hasn't been as easy as it sounds - even if chef Greg Ling (Raw, Django, Deuce) is doing his best work to date.

He has most of the contemporary dishes on this menu singing in perfect harmony, from plump Portuguese sardines topped with garlicky gremolata, to sweet crab salad tossed with shaved melons and snappy purslane leaves from Green Meadow Farm. His daily fish entrees have been spot-on, with perfect execution of simple, appealing combinations: seared red drum over tarragon-buttered leeks and mushrooms; flaky flounder and rustic potato-pepper hash sauced with spicy crab butter; Viking Village scallops in bisquey lobster sauce and corn. Sheer rounds of fried lemon add a bitter note of intrigue to the usual fried calamari.

His Oyster House burger – uniting the earthy minerality of dry-aged prime beef and blue cheese with the crowning jewels of fried oysters on a butter-toasted bun – is primally good.

But devising even such a novel twist for a burger pales in comparison to the challenge of reinventing snapper turtle soup, especially in a place where traditions are hallowed. Delete just a few of the 30-some ingredients from the old recipe, and the regulars are bound to howl. Remove the thickening roux from the usually gloppy soup, and they practically come unglued.

"They call this 'Old School'?!" my friend grouched at the brothy bowl described misleadingly on an earlier menu. He was already indignant about paying $3 for a once-free side of pepper hash ("too coarsely chopped; too vinegary").

The snapper soup has since been more accurately reflagged "new school," but that hasn't lessened the symbolism of its ever-changing execution. On its more liquid nights, I taste the Oyster House embracing its future vision confidently, letting the rich turtle stock, aromatic spice, and hearty chunks of brisket-tender meat make a bold statement. I've had more recent bowls as thick as gumbo, though, that made me wonder if the kitchen was starting to backslide. Other bowls had the texture right, but lost the delicate balance with too much garish clove.

It's a core issue of identity, no doubt, that the Oyster House has yet to settle. But there were other classics slightly out of register that need to be fine-tuned. The lobster roll, among the priciest entrees at $26, is all wrong, from the side-split hot-dog bun (should be top-split) to a dressing that's too dry. The minced veggies inside the crab cakes were too distractingly al dente. The oyster po-boy was ruined by a chewy roll and hyper-pickled onions. The oysters Rockefeller should never have been deconstructed into an oyster layered between a bed of spinach and a jiggly pouf of broiled hollandaise. The pureed green silk of a traditionally blended herb topping is Rockefeller's entire reason for being.

There are more than enough touchstones done right here, however, to warm a fish-house fanatic's heart. The grilled blue fish was the freshest I've had, the dusky meat updated with a summer salad of limas and heirloom tomatoes in vinaigrette. The clam chowder and lobster bisque were also unthickened, but their Lancaster-cream broths were vividly rich. The shrimp and lobster cocktails were pure raw-bar decadence, far superior to the too-lightly-grilled lobster entree. Steamed soft-shell belly clams were was the definition of New England clam-ocity.

The gumbo and fisherman's stew, meanwhile, were satisfying seafood meals in a bowl. A Pernod-scented broth for the stew was the next best thing to good bouillabaisse. And then, of course, there is that quintessential Philadelphian odd couple: fried oysters with chicken salad.

In the updating spirit, that salad is made from air-chilled Canadian birds that get brined with thyme before they're cooked for a date with Hellmann's. But it's the masterfully fried oysters that remind why we've missed the Oyster House all along. No matter which way you get them - smaller "Southern-style" oysters in corn flour, or plumper Philly-style pups in classic cracker meal - they are perfection in crust, with centers so delicate, they're like bite-size oyster souffles.

The combo is the classic Philly lunch, dating to 19th-century black caterers, the Union League's founding, and the long-gone fish houses of yore. But there's no denying the pleasure of cool poultry against hot mollusk on our 21st-century plates. As my friend purred with happiness at the raw bar beside me - our oyster house alive again! - we can only give thanks.