In the decade since it opened its red doors, many an expensive column inch has been splurged on the visual appearance of 5 Hertford Street—surely the most clubbable of all clubs in London’s buoyant clubland. Starved for any real gossip, owing to the Mayfair den’s extreme discretion, hacks across the capital have long put heavy emphasis on how the place looks instead—on its clashing, maximalist chintz, say, or its elaborate shell bar, or its procession of giant stuffed animals, or its cavalcade of red-nosed wedding dancers, or the surgical uplifts of their newly minted wives.

Far more interesting, though, is how 5 Hertford Street sounds—or, more precisely, how it doesn’t. Because the key to understanding the enduring power of this unique British institution is to understand its enduring, absorbing quietness too. The carpet is spread thick, like foie gras on Melba toast. The sofas are deep enough to swallow a Pomeranian, should anyone dare to bring one in. (Like all great country houses—and 5 Hertford Street is nothing if not a country house dropped into the middle of Mayfair—it likes its dogs big and proper; founder Robin Birley favors a blue whippet.)