The unofficial anthem of Buenos Aires is a classic tango from 1935, “Volver.” The name of the song means “to return,” and in it Carlos Gardel anticipates the mixed emotions of revisiting the city after many years. “To feel…that life is a puff of wind,” he croons, “that 20 years is nothing.” For me, it had been nearly 30 years since my last visit to Buenos Aires, a city to which I’d bought a one-way ticket as a young man with a wild dream of setting myself up as a foreign correspondent. By some miracle I established myself as a stringer for an array of international newspapers and was soon sharing a cheap apartment in the bohemian barrio of San Telmo with an NPR reporter. I became immersed in its half-European, half-Latin world, learning Spanish with the distinctive Argentine accent and lunfardo, the local slang; living on steak with chimichurri sauce; and attending raucous late-night avant-garde events at the legendary underground club Parakultural. Argentine democracy was still emerging from the long shadow of the military dictatorship that ruled in the late 1970s and early ’80s, whose “dirty war” resulted in an estimated 30,000 desaparecidos—“the disappeared.” BA could sometimes feel melancholy, claustrophobic, and conformist (every restaurant seemed to have the same beef and pasta menu), but it was rich with character and atmosphere. With its charming wood-paneled cafés and dapper, formal citizens, much of it felt like it had not changed since the 1930s.

My fear upon returning was that I would find Buenos Aires buried beneath a 21st-century Brooklyn-esque style. My trepidation dissolved as I rode in a taxi from the airport into downtown (now called the micro-center) along the world’s widest avenue, 9 de Julio, passing the familiar white obelisk, the city’s most famous landmark. Buenos Aires was more spacious and flower-filled than I’d recalled—the jacaranda trees were exploding in violet cascades—and the traffic seemed less chaotic, an achievement my driver credited to new highways and subway lines. But its architectural grandeur had barely been altered. Its streets are still lined with fine neoclassical buildings erected in the late-19th and early-20th centuries, when beef exports turned Argentines into the flush aristocrats of the Western Hemisphere. (Although dubbed the Paris of South America, the city’s flat geometric layout has always reminded me more of Madrid.)

In the old days the NPR reporter and I ironically nicknamed our arty La Bohème–style garret the Bolívar Palace, after its street address on Calle Bolívar. This time I started off in an actual palace: the Palacio Duhau, whose 1934 splendor evokes Versailles. It’s a beloved icon in the barrio Recoleta, the most opulent and traditional corner of the city. But when I went to grab a bite at the hotel restaurant, Gioia Cocina Botánica, in a landscaped garden surrounded by waterfalls and sculptures suitable for Louis XIV, I was startled to discover it was a haute-vegetarian place. As I was offered delicate mixes of tahini, lemon, and black garlic rolled in Swiss chard, I had to pinch myself. Vegetables in Buenos Aires?

My corner suite overlooked the Residencia Maguire, a Gothic mansion from 1891 with majestic gables and fantasy towers, whose sole resident, I was told, was an elderly woman who lived in Miami most of the year. I could gaze out at its decaying splendor and imagine ghostly soirees inside its gilded halls, then stroll around to the Recoleta cemetery, the enormous necropolis where Evita Perón is buried. Near her famous tomb is a surreal statue of a beloved Argentine boxer, Luis Ángel Firpo, the Wild Bull of the Pampas, posing in his robe as if ringside. But the barrio has changed with the times: A theater from 1919 where I used to go to see movies has been transformed into the El Ateneo Grand Splendid bookstore, the crimson curtain hanging intact overhead and gilded balconies now serving as reading rooms. Other alluring venues were new to me, such as Florería Atlántico, a gorgeous florist’s shop with an antique refrigerator that hides a doorway leading downstairs to a packed gin bar.

I decided to pay a visit to my old digs in the original bohemian district of San Telmo, a stone’s throw from the city’s Spanish colonial heart and the president’s mansion, the Casa Rosada, or Pink House. I was taken aback by the narrow street’s dreamlike quiet, since the buses that once ricocheted past, threatening life and limb, have been banned. Only a few steps away, though, the once sketchy district is busy with tourists converging on the 1897 cast-iron covered market, which is now an enticing high-end food court.

Strolling onward, I ended up in the riverside port area La Boca, whose colorfully painted alleys, framed by antique cranes, make it one of the most distinctive parts of the city. It is now dotted with museums like the Proa Foundation, which opened soon after I left, although, off the main drag, La Boca can still be a rough and seedy place. It was famously the birthplace of tango, which qualifies as Buenos Aires’s most original artistic creation. In its waterfront bars, lonely European immigrants sang melancholy arias about loss and homesickness, and men often danced with other men for lack of women partners, before tango was popularized in Paris in the early 1900s. While I was living in BA, the emotion-charged music was out of fashion and was sung mostly by debonair older gents and bejeweled grandes dames in mirror-lined venues like the Café Tortoni. But over the past two decades, it has been embraced by younger Porteños—“people of the port,” or BA natives. Professional tango shows are now ubiquitous, in La Boca and elsewhere, which can be fun but are essentially staged for tourists. More authentic are the milongas, erratically scheduled events for amateur aficionados at bars and dance halls all over the city.

A Porteño musician friend in New York tipped me off to one in the central neighborhood of Almagro, the childhood haunt of the tango god Gardel, at a bar-restaurant called Sanata, which is Argentine slang for “a tall tale.” The moment I stepped inside, I was enveloped by energy and music. The walls were covered with murals; many of them depicted Gardel and were painted by Ricardo Villar, a local artist nicknamed Crespi after a cheap wine. The beloved bon vivant Villar was a regular here until he had a heart attack at one of the tables. Images of musical heroes hang from the rafters. A four-piece group was performing the haunting tango on guitars and accordion while a dozen couples of all ages danced, swirling around the tables.

“The tango was revitalized after the economic crisis of 2001,” explained Sanata comanager Gloria Buccella, referring to the most traumatic of Argentina’s multiple economic collapses of the last few decades. “There was lots of soul-searching afterward, and young people started looking for what was real and unique in Argentine culture.” Her husband, David Sinatra, opened the bar about 15 years ago, and it has grown into a venue for talented up-and-coming musicians. Like many after-hours spots in BA, it really came to life after midnight, when some of the city’s finest veteran musicians arrived after their gigs to chat, drink, and jam together over red wine and empanadas.

Sanata turned out to be my first stop on a beguiling tango trail through Almagro. Buccella directed me around the corner to El Boliche de Roberto, a hopping 1893 venue where, according to legend, the teen Gardel performed before becoming an international star in the 1920s. At 1 a.m. the tango lovers spilled out onto the sidewalk into the warm night air. At 2 a.m. I headed around the corner to La Catedral Club, which seemed abandoned until I went up a ramshackle stairwell and discovered a cavernous dance hall in full swing. Located in a former dairy factory, it’s a vast space filled with mismatched furniture and walls covered with posters, artworks, and instruments. Although I began to lose steam around 4 a.m., the local crowds were still pouring in. A door attendant with a waist-length beard was shocked when I left: “We get busy at 5 a.m. You should stay!”