THOSE WERE YEARS when rents were low, when would-be writers, singers, dancers could afford to live in Manhattan’s (East, if not, West) Village, before everyone marginal was further marginalized by being squeezed out to Bushwick or Hoboken. Face-to-face encounters are essential to a city’s vitality, even among people who aren’t sure of each other’s names, for the exchange of ideas and to generate a sense of electricity. In the ’70s, creative people of all sorts could meet without plans, could give each other tips or discuss burgeoning theories or markets or movements.

In gay life, that’s called ‘‘cruising’’ (although the French equivalent, draguer, applies to all denominations). In the period before AIDS, the heyday of Studio 54 and Mineshaft, gays were on the verge of being dubbed trend-setters and tastemakers; Frank Rich even wrote a retrospective article for Esquire in 1987 in which he looked back at ‘‘the homosexualization of America.’’ But the outbreak of the plague in 1981 changed all that. Suddenly the glamour boys, with their showboat bodies and high-paying jobs, were Auschwitz skeletons covered with black spots, like Canova’s unfinished marble statues. No one wanted to exchange kisses with someone infected, especially not before the path of transmission was identified (Poppers? Mustaches? Mosquitoes? Tears?). Whereas straight guys had been intrigued with gay life before and could (almost) contemplate experimenting, suddenly the barrier between the two orientations shot up, higher than the Iron Curtain.