MILAN (AP) — Italian conductor Arturo Toscanini's legacies included abolishing encores at La Scala. So it was a playful touch when one of the maestro's musical heirs included a Verdi encore during a tribute at the Milan opera house marking the 150th anniversary of Toscanini's birth.

The Saturday night concert was part of a series of celebrations and commemorations planned across Italy to honor one of the 20th century's most enduring conductors, a man who defied Fascist leader Benito Mussolini, brought discipline and decorum to La Scala and popularized symphonic orchestral music in the United States.

Unlike composers whose works can be played and reinterpreted over time, the contribution of conductors "is written in water in a certain sense," said Harvey Sachs, a Toscanini biographer who helped curate an exhibit on the conductor at La Scala's museum that runs through June 4.

But Toscanini's fame has endured due to the musical rigor he imposed on orchestras and the fact that he was one of the first major conductors whose work was both recorded and broadcast live, Sachs said.

During his lifetime, Toscanini enjoyed renown around the world but particularly in his native Italy, where his focus was opera, and in the United States, the second home where he devoted his career to broadcasting symphonic music.

"In 1935, Time magazine published a statistic that 9 million Americans listened to his broadcast of the New York Philharmonic each week," Sachs said. "That was 7 percent of the population of the United States, adults and children, at that time. That would be like 22 million people tuning into a broadcast of symphonic music. It is almost unthinkable today."

He worked at La Scala both as principal conductor, for a decade from 1898, and musical director in the 1920s, and is credited with improving the discipline of musicians, expanding the repertoire and improving the behavior of unruly audience members.

It was Toscanini who installed an orchestra pit to help balance the sound of the musicians with the opera singers. He also had the lights turned down during performances and demanded silence from the audience, etiquette that is now the norm but then was a revolution, according to Toscanini expert Franco Pulcini, who collaborated on the La Scala exhibit.

By 1929, he'd had enough of fighting with theater directors over the expensive staging of operas and decided to focus on symphonic work. He shifted his career to the United States, where he was conducting the New York Philharmonic Orchestra at the time and had previously conducted the Metropolitan Opera.

"He realized that moving to the United States by conducting symphonic music, he had a much bigger audience for classical music," Pulcini said.

He went back and forth between Italy and the United States until his anti-Fascist political views — which included refusing to conduct the Fascist anthem — got him into trouble with Mussolini, and his passport was revoked.

In 1938, he went into self-exile in the U.S., where a year earlier he had taken the helm of the NBC Symphony Orchestra that was created for him. He continued there for 17 years.

His political views also led him to refuse in 1933 to return to the Bayreuth Festival dedicated to performances of operas by Richard Wagner, where he had been the first non-German conductor to appear.

Toscanini, who declined to attend because of the Wagner family's sympathies for Nazism, told Wagner's anti-fascist granddaughter, Friedelind, "This is the greatest sorrow of my life."

In a nod to Toscanini's strong politics, Italian conductor Riccardo Chailly closed Saturday's tribute concert with Verdi's "Hymn of Nations," which incorporates the Italian, French and British anthems and was seen at the time of its 1862 premier as presenting a view of European harmony.

The encore brought the audience, which included Italian President Sergio Mattarella and Culture Minister Dario Franceschini, to its feet.

The Toscanini anniversary tributes also included a sold-out concert in Bologna, the city where Toscanini was attacked by anti-Fascists in 1931, and with the opening of a new musical production center in Parma, the city of his birth.

Concerts by the La Scala Chamber orchestra are being performed this week in Washington and New York to coincide with the publication of the book "Toscanini, The Maestro: A Life in Pictures."