Mr. Abbado was one of the most revered conductors in the generation that came of age after World War II. Born to a musically prominent family in Milan, he trained at conservatories there and in Vienna. As an aspiring and fledgling conductor, he absorbed the rich aesthetic sensibility of Italy and the spirit of modernist experimentation cultivated in the Austrian capital.
His quiet charisma and boundless musical curiosity helped propel him to the most prestigious artistic appointments in Europe, including longtime associations with Milan’s La Scala (where he was musical director, a top leadership position, from 1971 to 1986), the Vienna State Opera (where he held the same title from 1986 to 1991), the Vienna Philharmonic and the Berlin Philharmonic (where he was chief conductor from 1989 to 2002).
Moving around Europe from one orchestra to another, Mr. Abbado risked the ire of conservative concertgoers by expanding the standard repertoire to include the avant-garde works of composers such as Arnold Schoenberg, Alban Berg, Luigi Dallapiccola and Luigi Nono.
“Musical history,” Mr. Abbado remarked shortly after his appointment at the Berlin Philharmonic, “does not end with Puccini.”
Mr. Abbado “respected the traditions,” F. Paul Driscoll, the editor in chief of Opera News, said in an interview, but also “pointed forward” to keep his houses vital.
Mr. Abbado regarded classical music not as a diversion for the privileged but rather as a sort of common trust. At La Scala, an opera house known for its attendance by the rich and royal of Europe, he took the orchestra out of the theater and into factories to perform for workers. He led the musicians in performances of instrumental works as well as operatic standards.
At the Berlin Philharmonic, he was credited with helping the orchestra develop an identity independent from that of his celebrated but at times overpowering predecessor, Herbert von Karajan.
Driscoll said Mr. Abbado “made it survive in a way that wasn’t connected with one person,” adding that he was “very connected with the future.”
Some conductors step onto the podium, with the orchestra before them and a crowd full of listeners seated behind them, and are enticed to indulge in flamboyance. Mr. Abbado was not among them.
“The conductor,” he once said, “should be able to change the sonority of an orchestra even with movements of his eyes. He should get what he wants with just a flick of his head.”
Among critics and astute observers, he became known for the delicate gestures he used to lead his musicians through the complexities of the score at hand.
“With a skyward gesture of his baton,” recounted New York Times music writer Daniel J. Wakin, describing a performance of Mahler’s Third Symphony in 2007, Mr. Abbado “sent the final chord soaring into nothingness, like a flock of birds flying heavenward.”
Mr. Abbado conducted from memory, once telling the Times that “communication with the orchestra is easier” without a score. He was roundly admired for his professional modesty.
“A conductor must consider himself first and foremost a musician,” he once told the Scotsman, an Edinburgh-based newspaper. “The whole idea of the conductor as some sort of god or dictator is absurd — especially as the age of the autocrat is now finished.”
Claudio Abbado was born on June 26, 1933, in Milan. His father, Michelangelo, was an internationally noted violinist; his mother, Maria Carmela, was a pianist and wrote children’s books. His older brother, Marcello, became a prominent conductor and composer.
In a house welling with music, Mr. Abbado decided at age 8 to become a conductor.
“When I heard Claude Debussy’s ‘Nocturnes,’ ” he told the Deutsche Welle news outlet, recalling a performance he attended at La Scala, “I immediately felt a desire to create this music one day myself.”
Mr. Abbado grew up in Milan during the dictatorship of Fascist leader Benito Mussolini. He told the Italian newspaper La Repubblica that his mother aided anti-Fascist partisans and helped Jews escape to Switzerland, and that many of them came back after the war to thank her. She was reportedly imprisoned for taking in a Jewish child.
Wartime deprivations notwithstanding, Mr. Abbado pursued his musical training. When other children scribbled graffiti promoting their favorite soccer teams, he was inspired to scrawl on a public wall the phrase “Viva Bartók” — for Béla Bartók, the contemporary Hungarian composer, one of his favorite musical figures.
During the war, graffiti was often used in Italy for political expression. The authorities saw the foreign name and assumed Bartók was an anti-Fascist organizer.
“The Gestapo came to the house to ask, ‘Who is the Partisan Bartók?’ ” Mr. Abbado recalled years later, according to the reference guide Contemporary Musicians. “They didn’t know about music.”
To send them away, Mr. Abbado produced a musical score.
He took piano and composition lessons before enrolling at the Verdi Conservatory in Milan, where his father was an instructor and where his brother Marcello became the director. At 18, having shown notable promise, Mr. Abbado was said to have been called to conduct before the revered Italian maestro Arturo Toscanini.
After his graduation, Mr. Abbado studied at the Vienna Academy of Music, where his teachers included the influential conductor Hans Swarowsky.
One of his classmates was the future world-renowned conductor Zubin Mehta. The two young men joined the city’s Musikfreunde chorus — not because they wanted to sing but because they wanted to observe the conductors, who included von Karajan and Bruno Walter.
Mr. Abbado made his conducting debut in Trieste, Italy, in 1958. The next year, in the same city, he led his first opera, Sergei Prokofiev’s “The Love for Three Oranges.”
In 1958, Mr. Abbado and Mehta went to the Berkshire Music Center at Tanglewood in Massachusetts, where Mr. Abbado received the Serge Koussevitzky conducting prize. Mehta and Gustav Meier also received prestigious conducting awards that year. In 1963, Mr. Abbado won the Mitropoulos International Music Competition in New York, which brought him more attention and helped spark his career.
Mr. Abbado “had none of the usual percussive tastes of the pianistic conductor,” Time magazine reported. “Instead, he even trusted the beaters and blowers in the orchestra to come in without cues while he painted tones in the violin section.”
Besides his work in Milan, Vienna and Berlin, Mr. Abbado held years-long relationships with the London and Chicago symphony orchestras. He also appeared with groups including the New York Philharmonic, the Philadelphia Orchestra and Washington’s National Symphony Orchestra.
Washington Post classical music critic Joseph McLellan once described Mr. Abbado’s appearance with the NSO in 1979 — a performance that featured a relatively young soprano, Kiri Te Kanawa, singing Strauss and Mahler — as “one of the great moments in the orchestra’s history.”
Mr. Abbado’s extensive recordings were acclaimed for their artistic clarity. Among his opera recordings were Verdi’s “Falstaff” with the Berlin Philharmonic and “Simon Boccanegra,” “Macbeth” and “Don Carlos” with La Scala. Mr. Abbado also recorded the works of Mozart, Beethoven and Mahler, among many others.
He was revered for his dedication to the young artists who would carry on the traditions of classical music after his retirement. He created the Mahler Youth Orchestra and was the founding musical director of the European Union Youth Orchestra.
His first marriage, to Giovanna Cavazzoni, produced his children Daniele and Alessandra and ended in divorce. He later married a dress designer, Gabriella Cantalupi, with whom he had a son, Sebastiano. A relationship with Russian violinist Viktoria Mullova, who was 26 years his junior, produced a son, Misha.
Survivors, according to the London Guardian, include his second wife; four children; two brothers; and a sister.
Mr. Abbado once reflected on his understated manner — his calling card over the years — and the primacy of music over accolades.
“You know, there was a great conductor named Hans Knappertsbusch,” he told the Times in 1973. “After a concert, he would leave and never come out for bows. Years ago, I used to be somewhat like that. Now I take the time to be polite.
“Look,” he continued, “I like the reaction of the audience. I’m not sincere if I don’t say that, but it still embarrasses me to take bows. I’m not a showman. I hate all that.”