Sometimes, when Tommy D’Alesandro told you a story, he’d lean in close and cup his hand, as though whispering a secret at religious confession. He didn’t want you to miss a word. Then he’d let loose with an uproarious tale, followed by one of the greatest laughs in the entire Western Hemisphere.

It was a pleasure to be around him just to hear the laugh, so unfettered that it sounded like something between a hiccup and an aria.

Baltimore heard that laugh, and those stories, for 90 years, until Thomas D’Alesandro III got away from us Sunday, Oct. 20.

To the very end, he was “Young Tommy” because his dad, “Tommy the Elder,” had been the city’s three-term mayor during the post-war boom years. And he was Nancy’s brother, because his little sister was Nancy Pelosi, the most powerful woman in American political history.

And he was “Mayor Tommy” himself for a term, and then walked away from it. The common wisdom (which Tommy denied) is that the 1968 riots, following the assassination of Dr. Martin Luther King Jr. and just four months after Tommy got the job, took the heart out of him.

That explanation always carried great irony. D’Alesandro was the first mayor to appoint an African-American as city solicitor, as public school superintendent, as fire commissioner. He pushed through a civil rights bill guaranteeing equal access to public accommodations, a major accomplishment in a city that still had a southern orientation. He considered Martin Luther King Jr. not only an ally but a friend.

But he retired after a single term, and opened the door to William Donald Schaefer’s first mayoral campaign, run by Ted Venetoulis.

Venetoulis, later Baltimore County executive, was close friends with D’Alesandro. “He brought out the best in people,” a choked-up Venetoulis said when he got the news of Tommy’s death. “And he brought out the best in politics.”

By “politics,” though, he meant more than the stuff of elections. It was about understanding the texture of cities, and the give-and-take of ethnic sensibilities.

Some years back, D’Alesandro helped me with a book I was writing, called “Journeys to the Heart of Baltimore.” It’s about the American melting pot, in which the Italian-American Tommy exulted. He got his instincts from his father.

“I was in two worlds from the very beginning,” he said. “I traveled with my father all around the city. In those days, every neighborhood was identified by their ethnicity. … The cement, the bond, was that they’re all one ethnic background. They lived in a very parochial world, right up through World War II.”

He remembered teenage dances, “and all the groups in these different corners. The Casino in Patterson Park, The Alcazar. The Italians stood on one side, the Poles on the other. It was difficult to cross over and ask a Polish girl to dance. Fights would break out, which would break up only when the band would play, ‘The Star-Spangled Banner,’ and everybody came to attention. So you danced with those that you brought.”

“Sounds like the dance in ‘West Side Story,’” I said.

“A lot like that,” he said. “I’ll tell you a story, one time I was at Luge’s confectionary store, where Sabatino’s is now. I was getting a coke, looking out the window. Somebody says, ‘Isn’t that awful? Isn’t that awful?’ Says a guy up on Albemarle Street got engaged to a Polish girl.

“I said, ‘What’s wrong with that? What’s wrong with that?’ He says, ‘You’re supposed to marry an Italian girl.’ Heresy. In the ‘40s, it was heresy. And now, hopefully, hopefully …”

The words trailed off. It’s the eternal American sensitivity, which D’Alesandro understood in his bones. Every ethnic minority wants to feel fully American, yet hold onto the stuff that makes us unique and gives us tribal pride.

“Today,” D’Alesandro said on that morning years ago, “my son’s married to an Asian girl. My other son, a Spanish girl. Look, as long as they’re in love, that’s all that counts.”

“But me,” he said, reaching for a newspaper sports page, “I’m still looking for Italians in the box score.”

And then came that laugh of his, which was beautiful. Baltimore heard it for 90 years. It wasn’t long enough.

A former Baltimore Sun columnist and WJZ-TV commentator, Michael Olesker is the author of six books, most recently “Front Stoops in the Fifties: Baltimore Legends Come of Age” (Johns Hopkins University Press).