Russian conductor Valery Gergiev and German opera singer Jonas Kaufmann are seen with the Vienna Philharmonic Orchestra on stage during the Summer Night Concert in the setting of Schoenbrunn Palace amid the coronavirus disease (COVID-19) outbreak in Vienna, Austria September 18, 2020. REUTERS/Lisi Niesner

German opera singer Jonas Kaufmann gives an elbow bump with a musician of the Vienna Philharmonic Orchestra on stage during the Summer Night Concert in the setting of Schoenbrunn Palace amid the coronavirus disease (COVID-19) outbreak in Vienna, Austria September 18, 2020. REUTERS/Lisi Niesner

German opera singer Jonas Kaufmann is seen with the Vienna Philharmonic Orchestra on stage during the Summer Night Concert in the setting of Schoenbrunn Palace amid the coronavirus disease (COVID-19) outbreak in Vienna, Austria September 18, 2020. REUTERS/Lisi Niesner

German opera singer Jonas Kaufmann is seen with the Vienna Philharmonic Orchestra on stage during the Summer Night Concert in the setting of Schoenbrunn Palace amid the coronavirus disease (COVID-19) outbreak in Vienna, Austria September 18, 2020. REUTERS/Lisi Niesner

German opera singer Jonas Kaufmann is seen with the Vienna Philharmonic Orchestra on stage during the Summer Night Concert in the setting of Schoenbrunn Palace amid the coronavirus disease (COVID-19) outbreak in Vienna, Austria September 18, 2020. REUTERS/Lisi Niesner

Russian conductor Valery Gergiev and German opera singer Jonas Kaufmann are seen with the Vienna Philharmonic Orchestra on stage during the Summer Night Concert in the setting of Schoenbrunn Palace amid the coronavirus disease (COVID-19) outbreak in Vienna, Austria September 18, 2020. REUTERS/Lisi Niesner

German opera singer Jonas Kaufmann is seen with the Vienna Philharmonic Orchestra on stage during the Summer Night Concert in the setting of Schoenbrunn Palace amid the coronavirus disease (COVID-19) outbreak in Vienna, Austria September 18, 2020. REUTERS/Lisi Niesner

German opera singer Jonas Kaufmann sings as the Vienna Philharmonic Orchestra performs on stage during the Summer Night Concert in the setting of Schoenbrunn Palace amid the coronavirus disease (COVID-19) outbreak in Vienna, Austria September 18, 2020. REUTERS/Lisi Niesner

German opera singer Jonas Kaufmann sings as the Vienna Philharmonic Orchestra performs on stage during the Summer Night Concert in the setting of Schoenbrunn Palace amid the coronavirus disease (COVID-19) outbreak in Vienna, Austria September 18, 2020. REUTERS/Lisi Niesner

Egypt's Minister of Culture Enas Abdel-Dayem (C) sits among an audience wearing protective face masks and keeping social distance during the first concert of the Cairo Symphonic Orchestra after the Cairo Opera House reopened, amid concerns about the spread of the coronavirus disease (COVID-19), in Cairo, Egypt July 18, 2020. REUTERS/Mohamed Abd El Ghany

Audience wearing protective face masks and keeping social distance listen to the first concert of the Cairo Symphonic Orchestra after the Cairo Opera House reopened, amid concerns about the spread of the coronavirus disease (COVID-19), in Cairo, Egypt July 18, 2020. REUTERS/Mohamed Abd El Ghany

A boy sings military songs during the first concert of the Cairo Symphonic Orchestra after the Cairo Opera House reopened, amid concerns about the spread of the coronavirus disease (COVID-19), in Cairo, Egypt July 18, 2020. REUTERS/Mohamed Abd El Ghany

A man wearing protective face mask listens to the first concert of the Cairo Symphonic Orchestra after the Cairo Opera House reopened, amid concerns about the spread of the coronavirus disease (COVID-19), in Cairo, Egypt July 18, 2020. REUTERS/Mohamed Abd El Ghany

Audience wearing protective face masks and keeping social distance listen to the first concert of the Cairo Symphonic Orchestra after the Cairo Opera House reopened, amid concerns about the spread of the coronavirus disease (COVID-19), in Cairo, Egypt. July 18, 2020. REUTERS/Mohamed Abd El Ghany

Audience wearing protective face masks and keeping social distance listen to the first concert of the Cairo Symphonic Orchestra after the Cairo Opera House reopened, amid concerns about the spread of the coronavirus disease (COVID-19), in Cairo, Egypt. July 18, 2020. REUTERS/Mohamed Abd El Ghany

A woman wearing a protective mask sits on a social distancing seat to prevent the spread of the coronavirus disease (COVID-19) as she attends the Syrian National Symphony Orchestra at the Opera House in Damascus, Syria July 2, 2020. Picture taken July 2, 2020. REUTERS/Yamam Al Shaar

Members of the Syrian National Symphony Orchestra practice before a performance at the Opera House in Damascus, Syria July 2, 2020. Picture taken July 2, 2020. REUTERS/Yamam Al Shaar

Missak Baghboudarian, a conductor of the Syrian National Symphony Orchestra, gestures during a practice before a performance at the Opera House in Damascus, Syria July 2, 2020. Picture taken July 2, 2020. REUTERS/Yamam Al Shaar

Members of the Syrian National Symphony Orchestra practice before a performance at the Opera House in Damascus, Syria July 2, 2020. Picture taken July 2, 2020. REUTERS/Yamam Al Shaar

Members of the Syrian National Symphony Orchestra practice before a performance at the Opera House in Damascus, Syria July 2, 2020. Picture taken July 2, 2020. REUTERS/Yamam Al Shaar

Missak Baghboudarian, a conductor of the Syrian National Symphony Orchestra, speaks to an audience at the Opera House in Damascus, Syria July 2, 2020. Picture taken July 2, 2020. REUTERS/Yamam Al Shaar

Members of the Paris Opera's orchestra play an improvised open-air concert outside the Opera Garnier during a demonstration of French lawyers on strike against French government's pension reform bill and justice in front of the Opera Garnier in Paris, France, March 11, 2020. REUTERS/Benoit Tessier?

Members of the Paris Opera's orchestra play an improvised open-air concert outside the Opera Garnier during a demonstration of French lawyers on strike against French government's pension reform bill and justice in front of the Opera Garnier in Paris, France, March 11, 2020. REUTERS/Benoit Tessier?

Musicians of the Paris Opera's orchestra react after playing an improvised open-air concert outside the Opera Garnier to protest the government's proposed pension reform, which affects the state-employed musicians' special status in Paris, France, January 18, 2020. REUTERS/Charles Platiau

Musicians of the Paris Opera's orchestra react after playing an improvised open-air concert outside the Opera Garnier to protest the government's proposed pension reform, which affects the state-employed musicians' special status in Paris, France, January 18, 2020. REUTERS/Charles Platiau

Musicians of the Paris Opera's orchestra play an improvised open-air concert outside the Opera Garnier to protest the government's proposed pension reform, which affects the state-employed musicians' special status in Paris, France, January 18, 2020. REUTERS/Charles Platiau

Musicians of the Paris Opera's orchestra play an improvised open-air concert outside the Opera Garnier to protest the government's proposed pension reform, which affects the state-employed musicians' special status in Paris, France, January 18, 2020. REUTERS/Charles Platiau

Conductor Michel Dietlin and members of the Paris Opera's orchestra play an improvised open-air concert outside the Opera Garnier to protest the government's proposed pension reform, which affects the state-employed musicians' special status in Paris, France, January 18, 2020. REUTERS/Charles Platiau

Musicians of the Paris Opera's orchestra play an improvised open-air concert outside the Opera Garnier to protest the government's proposed pension reform, which affects the state-employed musicians' special status in Paris, France, January 18, 2020. REUTERS/Charles Platiau

Conductor Michel Dietlin and members of the Paris Opera's orchestra play an improvised open-air concert outside the Opera Garnier to protest the government's proposed pension reform, which affects the state-employed musicians' special status in Paris, France, January 18, 2020. REUTERS/Charles Platiau

Conductor Michel Dietlin and members of the Paris Opera's orchestra play an improvised open-air concert outside the Opera Garnier to protest the government's proposed pension reform, which affects the state-employed musicians' special status in Paris, France, January 18, 2020. REUTERS/Charles Platiau

Conductor Michel Dietlin and members of the Paris Opera's orchestra play an improvised open-air concert outside the Opera Garnier to protest the government's proposed pension reform, which affects the state-employed musicians' special status in Paris, France, January 18, 2020. REUTERS/Charles Platiau

Members of the Paris Opera's orchestra, workers of the Paris transport network (RATP) French SNCF railway workers and teachers demonstrate at the city's Place de la Bastille square to protest the government's proposed pension reform in Paris, France, December 31, 2019. REUTERS/Charles Platiau

French CGT labour union leader Philippe Martinez attends an improvised open-air concert by members of the Paris Opera's orchestra at the city's Place de la Bastille square to protest the government's proposed pension reform, which affects the state-employed musicians' special status in Paris, France, December 31, 2019. REUTERS/Charles Platiau

Members of the Paris Opera's orchestra play an improvised open-air concert at the city's Place de la Bastille square to protest the government's proposed pension reform, which affects the state-employed musicians' special status in Paris, France, December 31, 2019. REUTERS/Charles Platiau

Members of the Paris Opera's orchestra play an improvised open-air concert at the city's Place de la Bastille square to protest the government's proposed pension reform, which affects the state-employed musicians' special status in Paris, France, December 31, 2019. REUTERS/Charles Platiau

Academic Symphony Orchestra "INSO-Lviv" rehearse a scene from the opera "Aida" originally set in the Old Kingdom of Egypt and composed by Giuseppe Verdi at the Temple of Queen Hatshepsut in West Bank of Luxor, Egypt, October 24, 2019. REUTERS/Amr Abdallah Dalsh

Maestro, Mohamed Saad Pasha, leads Opera Orchestra and ballet members during the performance of "Cleopatra Ballet" the historical story of the queen of Egypt "Cleopatra" at Opera House in Cairo, Egypt, October 18, 2019. Picture taken October 18, 2019. REUTERS/Amr Abdallah Dalsh

A musician of an orchestra of the Opera Studio under the Ukrainian National Academy of Music sits after a rehearsal in Kiev, Ukraine April 5, 2018. REUTERS/Valentyn Ogirenko

A musician of an orchestra of the Opera Studio under the Ukrainian National Academy of Music plays the cello during a rehearsal in Kiev, Ukraine April 5, 2018. REUTERS/Valentyn Ogirenko

Musicians of an orchestra of the Opera Studio under the Ukrainian National Academy of Music rehearse in Kiev, Ukraine April 5, 2018. REUTERS/Valentyn Ogirenko

A view shows music sheets during a rehearsal of an orchestra of the Opera Studio under the Ukrainian National Academy of Music in Kiev, Ukraine April 5, 2018. REUTERS/Valentyn Ogirenko

Musicians of an orchestra of the Opera Studio under the Ukrainian National Academy of Music rehearse in Kiev, Ukraine April 5, 2018. REUTERS/Valentyn Ogirenko

A view shows music sheets during a rehearsal of an orchestra of the Opera Studio under the Ukrainian National Academy of Music in Kiev, Ukraine April 5, 2018. REUTERS/Valentyn Ogirenko

The orchestra and singers perform on the stage of the National Centre for the Performing Arts during "Jinsha River" opera's final dress rehearsal in Beijing, China July 27, 2017. "Jinsha River", the opera adapted from a novel of the same name telling the story of the Red Army on the long march in Tibetan area in 1935, will have its premiere as the country marks the 90th anniversary of the founding of Chinese People's Liberation Army (PLA). REUTERS/Damir Sagolj

A member of the orchestra uses a mobile phone before "Jinsha River" opera's final dress rehearsal at the National Centre for the Performing Arts in Beijing, China July 27, 2017. "Jinsha River", the opera adapted from a novel of the same name telling the story of the Red Army on the long march in Tibetan area in 1935, will have its premiere as the country marks the 90th anniversary of the founding of Chinese People's Liberation Army (PLA). REUTERS/Damir Sagolj

Members of the orchestra practice on the stage of the National Centre for the Performing Arts before "Jinsha River" opera's final dress rehearsal in Beijing, China July 27, 2017. "Jinsha River", the opera adapted from a novel of the same name telling the story of the Red Army on the long march in Tibetan area in 1935, will have its premiere as the country marks the 90th anniversary of the founding of Chinese People's Liberation Army (PLA). REUTERS/Damir Sagolj

The orchestra and actors perform on the stage of the National Centre for the Performing Arts during "Jinsha River" opera's final dress rehearsal in Beijing, China July 27, 2017. "Jinsha River", the opera adapted from a novel of the same name telling the story of the Red Army on the long march in Tibetan area in 1935, will have its premiere as the country marks the 90th anniversary of the founding of Chinese People's Liberation Army (PLA). REUTERS/Damir Sagolj

Aleksandra Ryzhenkova, a musician of the State Opera and Ballet Theatre's orchestra, who is also a model of the SibPlus Models agency and a participant of the Miss Doughnut 2016 beauty competition, plays a violoncello during a rehearsal at the theatre in Krasnoyarsk, Siberia, Russia March 3, 2017. Picture taken March 3, 2017. REUTERS/Ilya Naymushin

Italian conductor Francesco Cilluffo directs the orchestra during the Giacomo Puccini's Madame Butterfly opera, in a free and open-air performance at Park HaYarkon in Tel Aviv, Israel September 15, 2016. REUTERS/Amir Cohen

Opera singer Placido Domingo turns to the audience after conducting the State Opera Orchestra during a dress rehearsal the day before the traditional Opera Ball in Vienna, Austria, February 3, 2016. REUTERS/Heinz-Peter Bader

A general view shows the Berliner Philharmonie concert hall seat of the Berliner Philharmonic orchestra in Berlin, Germany, June 22, 2015. The Berlin Philharmonic has picked Kirill Petrenko, general music director at the Bavarian State Opera, to become its next artistic director and chief conductor, according to German media reports. Petrenko, a 43-year-old Russian who emigrated to Austria with his family when he was a teenager, would succeed Briton Simon Rattle in 2018, becoming one of an elite group of directors to lead the Philharmonic, one of the world's leading orchestras. REUTERS/Fabrizio Bensch

James Judd (R) conducts the orchestra as performers are seen on the stage during a dress rehearsal for Carmina Burana by Carl Orff ahead of the Israeli Opera Festival, which begins Thursday, at Masada June 3, 2015. Carl Orff's Carmina Burana, composed in the Nazi era, will be showcased at the Israeli opera festival against the backdrop of a towering desert plateau that stands as a symbol of Jewish resistance and sacrifice. Picture taken June 3, 2015. REUTERS/Ammar Awad

Costumed performers and members of the orchestra take part in a dress rehearsal for Giacomo Puccini's Tosca ahead of the Israeli Opera Festival at Masada, which begins Thursday, June 1, 2015. According to the ancient historian Josephus, Masada was the site of a Roman siege that ended in 73 AD when hundreds of Jewish rebels committed mass suicide rather than fall as slaves to the Romans. Built by King Herod as a winter palace between 37-31 BC, Masada is a UNESCO World Heritage site and has for decades been a source of archaeological fascination. Picture taken June 1, 2015. REUTERS/Nir Elias

Musicians of Donbass Opera Theatre orchestra, also known as the Donetsk Opera Theatre, prepare for a performance in Donetsk December 13, 2014. Russian soprano Anna Netrebko, one of the biggest names in international opera, has stirred controversy by posing with the flag of Ukraine's pro-Russian rebels and making a donation to the opera house in the separatists' main stronghold, Donetsk. Netrebko said on Facebook she had not recognized the flag of "Novorossiya" (New Russia) when she posed alongside a rebel official on Sunday and entrusted him with the donation of 1 million roubles ($18,439). REUTERS/Maxim Shemetov (UKRAINE - Tags: SOCIETY CIVIL UNREST POLITICS)

A violinist of Donbass Opera Theatre orchestra, also known as the Donetsk Opera Theatre, Dmitry Gorshkov prepares for a performance in Donetsk December 13, 2014. Russian soprano Anna Netrebko, one of the biggest names in international opera, has stirred controversy by posing with the flag of Ukraine's pro-Russian rebels and making a donation to the opera house in the separatists' main stronghold, Donetsk. Netrebko said on Facebook she had not recognized the flag of "Novorossiya" (New Russia) when she posed alongside a rebel official on Sunday and entrusted him with the donation of 1 million roubles ($18,439). REUTERS/Maxim Shemetov (UKRAINE - Tags: SOCIETY CIVIL UNREST POLITICS)

Union orchestra musicians and chorus members of New York's Metropolitan Opera gather at a rally near Lincoln Center in New York City, August 1, 2014. New York's Metropolitan Opera agreed to extend negotiations with its labor unions for 72 hours, preventing a threatened lockout at the nation's largest performing arts organization, the Met said late on Thursday. REUTERS/Mike Segar (UNITED STATES - Tags: SOCIETY BUSINESS EMPLOYMENT)

Union orchestra musicians of New York's Metropolitan Opera perform as they attend a rally with chorus members and others near Lincoln Center in New York City, August 1, 2014. New York's Metropolitan Opera agreed to extend negotiations with its labor unions for 72 hours, preventing a threatened lockout at the nation's largest performing arts organization, the Met said late on Thursday. REUTERS/Mike Segar (UNITED STATES - Tags: SOCIETY BUSINESS EMPLOYMENT)

Union orchestra musicians of New York's Metropolitan Opera perform as they attend a rally near Lincoln Center in New York City, August 1, 2014. New York's Metropolitan Opera agreed to extend negotiations with its labor unions for 72 hours, preventing a threatened lockout at the nation's largest performing arts organization, the Met said late on Thursday. REUTERS/Mike Segar (UNITED STATES - Tags: BUSINESS EMPLOYMENT SOCIETY)

A woman dances with a man on stilts as Union orchestra musicians and chorus members of New York's Metropolitan Opera attend a rally near Lincoln Center in New York City, August 1, 2014. New York's Metropolitan Opera agreed to extend negotiations with its labor unions for 72 hours, preventing a threatened lockout at the nation's largest performing arts organization, the Met said late on Thursday. REUTERS/Mike Segar (UNITED STATES - Tags: SOCIETY BUSINESS EMPLOYMENT)