Mart Crowley, the author of the groundbreaking gay play “The Boys in the Band,” lives in a Manhattan apartment building that he used to visit frequently, for parties, in the late 1960s, when “Boys” had its theatrical debut. It’s on East 54th Street, No. 405, and its nickname, he told me, used to be “four of five,” because that was supposedly the ratio of gay residents.

That is not the ratio now. “It’s all yuppies and kids in strollers and all of that — and a few old codgers,” Crowley, 82, said over a recent lunch. The gays have scattered, not just from that building but from others, and we’ve distributed ourselves throughout the city — and throughout society. Gay sanctuaries are vanishing.

Is that true of gay culture and gay identity, too? I increasingly get the sense that gayness itself has scattered, becoming something more various and harder to define. “Gay” tells you about a person’s lusts and loves, but it used to tell you more — about his or her boldness, irreverence, independence. It connoted a particular journey and pronounced struggle, and had its own soundtrack, sartorial flourishes and short list of celebrity icons. Not so anymore.

These thoughts came to mind as “Boys” comes back into view. For its 50th anniversary, it’s getting its first-ever Broadway production, with an all-gay, all-star cast including Jim Parsons, Matt Bomer and Zachary Quinto. Previews begin Monday; the show opens May 31. I’ll be fascinated to see what audiences make of this campy, catty portrait of a group of gay men who talk in code, traffic in secrecy and have carved out something separate that is not exactly peace.