Isabella Stewart Gardner was a legendary hostess who unveiled her prized palace at a 1903 blowout brimming with Champagne, doughnuts and boldfaced names, so she’d surely smile to see the party that draws art lovers there each month, an often sold-out soiree that always offers something new to see, hear and do. Consider recent installment Madonna/Madonna, which had revelers roaming the galleries on a scavenger hunt for visions of the Virgin Mary, moving to the likes of “Like a Virgin” via a vinyl-spinning DJ, striking a pose in the studio for a collaborative art project and taking in exhibit-inspired talks and performances. And there’s nothing quite like sipping cocktails around that courtyard garden, a lush oasis even in the depths of February.