JERUSALEM (AP) _ World-renowned conductor Daniel Barenboim first conducted a lively debate with the audience for 30 minutes, punctuated by periodic insults directed at him, and then led the Berlin Staatskapelle in playing the music of Richard Wagner, Hitler's favorite composer.
Barenboim, who is Jewish, had agreed beforehand to observe the informal ban on Wagner in Israel and not to perform his music at Israel's most prestigious arts festival.
The surprise performance drew a rousing ovation from the audience Saturday night. The debate continued on Sunday.
Jerusalem's Mayor Ehud Olmert said the city will have to reconsider its future relations with Barenboim after he performed the overture to Wagner's opera ``Tristan und Isolde'' as an encore at the Israel Festival.
``What Barenboim did was brazen, arrogant, uncivilized and insensitive,'' Olmert told Israel's army radio.
``We will urge all the Israeli orchestras to boycott Daniel Barenboim,'' said Nazi-hunter Ephraim Zuroff, director of the Israeli branch of the Los Angeles-based Simon Wiesenthal Center.
However, most of the audience gave Barenboim a standing ovation for his initiative. A minority protested, some of them walking out, others shouting, ``fascist,'' ``concentration camp music,'' ``it's a disgrace'' and other insults.
Holocaust survivors were to be found in both groups.
``Wagner was a giant anti-Semite but he was also a great musician,'' said 67-year-old engineer Michael Avraham, himself a Holocaust survivor. ``Of course I'm against his views, but I'm not against his music.''
The musicians of the prestigious Staatskapelle listened _ but presumably did not understand _ as Barenboim debated in Hebrew with the Israeli audience. One of the protesters shouted from the balcony, while others in the auditorium told the man to go home and not to disturb the performance.
The emotional debate lasted almost 30 minutes and was unprecedented in the long-running controversy over whether Wagner's music should be played in Israel.
In the original program of the festival, the Staatkapelle was to perform the first act of Wagner's opera ``Die Walkuere,'' with three singers, including the renowned Placido Domingo.
The festival management backed down, however, after protests from various groups and pressure from politicians. It asked Barenboim to consider an alternative program, and he agreed instead to play Schumann's Symphony No. 4 and Stravinsky's ``Rite of Spring.''
After completing the scheduled program, Barenboim asked the audience whether they wanted him to play a Wagner piece as an encore. He told them this was his personal initiative.
``You can be angry with me, but please don't be angry with the orchestra or the festival management,'' he said.
Most of the audience immediately broke into applause, but a few people started shouting against it.
Barenboim appealed to those whose feelings would be offended to leave if they wished, but to allow the others to hear. When the music began, a small number of protesters banged doors and shouted ``no,'' but after a few minutes the noise stopped and the overture was completed without further interruptions.
Wagner died 50 years before Adolf Hitler came to power in Germany, but his music inspired Nazi cultural propaganda. For over 50 years, there has been an informal ban on the public performance of Wagner's works in Israel, although it is occasionally played on Israeli state radio.
In 1981 the Israel Philharmonic Orchestra tried to play a piece from ``Tristan und Isolde,'' also as an encore, but a Holocaust survivor jumped onto the stage, opened his shirt and showed scars inflicted in a Nazi concentration camp. Conductor Zubin Mehta stopped the performance.
Barenboim was born in Argentina, grew up in Israel and lives in Berlin.