Question: The Mariinsky Theatre Second Stage hosted which Russo-Austrian soprano on May 2, 2013?
Context: The Mariinsky Theater Second Stage is the second part of a theatre complex which is made up of the original 1860 Mariinsky Theatre and the 2007 Mariinsky Theatre Concert Hall.  The Second Stage has been completed and a gala concert celebrating the opening, and featuring such luminaries as Plácido Domingo, Rene Pape, Anna Netrebko, and many others, was presented on 2 May 2013.  The concert also celebrated the sixtieth birthday of musical director Valery Gergiev. Aida Garifullina (born 30 September 1987) is a Russian operatic soprano of Tatar origin.  She was the winner of the 2013 Operalia competition and has featured in a number of productions staged at the Mariinsky Theatre, St. Petersburg and the Wiener Staatsoper.  She has a recording contract with Decca Records. Anna Yuryevna Netrebko (Russian: Анна Юрьевна Нетребко , born 18 September 1971) is a Russian operatic soprano.  She now holds dual Russian and Austrian citizenship and currently resides in Vienna, Austria, and in New York City. Groezrock is an annual music festival that takes place in Meerhout, Belgium.  It started out as a small rock and pop festival with a few hundred people attending, but has evolved into a large punk rock/hardcore punk festival, with attendances now exceeding 30000.  Since 2003 there have been stages in 2 marquees.  The second stage, Back-to-basics-stage, is reserved for more hardcore oriented bands.  Since 2006 the festival has taken place over 2 days, and still has two stages.  In 2007 the main stage was called the "We Rock Stage" and the second stage "Eastpak Core Stage". Olga Peretyatko (Russian: Ольга Перетятько ; born 21 May 1980 in Leningrad, now Saint Petersburg) is a Russian operatic soprano.  As a child Peretyatko sang in the children's choir of the Mariinsky Theatre.  As a student of the Hamburg Opera Studio she received the second prize at Operalia Competition (2007), an event sponsored by tenor Plácido Domingo. Viktoria Yastrebova (Russian: Виктория Ястребова , also known as Victoria Yastrebova) is a Russian operatic soprano.  She is currently a principal of the Mariinsky Theatre in Saint Petersburg, Russia. Julia Novikova (Russian: Юлия Новикова) is a Russian coloratura soprano opera singer.  She was born in Leningrad, Russia, in 1983.  As a child her parents took her to see performances at Mariinsky Theatre.  In 2006 she graduated from Saint Petersburg Conservatory after studying opera singing under Professor Olga Kondina. Eleonora Vindau (Russian: Элеонора Виндау ) (born 19 August 1986) is a Ukrainian soprano opera singer.  She sang the role of Dunyasha in the world premiere of Alexander Smelkov's opera "The Station Master", staged at the Concert Hall of the Mariinsky Theatre in 2011 and is a laureate of IV All-Russian Nadezhda Obukhova Young Opera Singers' Competition (Lipetsk, 2008) and the VIII International Rimsky-Korsakov Young Opera Singers' Competition (St Petersburg, 2008) Artyom Melikhov is a Russian tenor singer who was born in Saint Petersburg.  He graduated from both the Glinka Choral School and Saint Petersburg Conservatory where he was under guidance from Yelizaveta Kudryavtseva till 2006.  In 2008 under guidance from Valery Gergiev he played a role of one of the Japanese envoys in "Le Rossignol" opera and during the same year played a soloist role in "Chimes" at the Mariinsky Theatre.  In 2009 he had his first appearance with Mariinsky Theatre where he played in an opera called "War and Peace".  That year was followed by such 2010 debuts as the "The Mystery of the Apostle Paul" in which he sang in a role of "Nero" at the Mariinsky Theatre and another "War and Peace" performance, this time at the John F. Kennedy Center for the Performing Arts.  In 2011 he became the Mariinsky Academy of Young Singers soloist and the same year performed the role of "Ovlur" in an opera called "Prince Igor" following by his appearance in "Dead Souls" and "Ariadne auf Naxos".  In May 2013 he was "Rienzi" performer at the Saratov Opera under Alexei Stepanyuk's baton and the same year sang at the Carmina Burana opera after which he went on a tour to Naples where he performed at the Teatro di San Carlo. The Mariinsky Theatre (Russian: Мариинский театр , Mariinskiy Teatr, also spelled Maryinsky or Mariyinsky) is a historic theatre of opera and ballet in Saint Petersburg, Russia.  Opened in 1860, it became the preeminent music theatre of late 19th century Russia, where many of the stage masterpieces of Tchaikovsky, Mussorgsky, and Rimsky-Korsakov received their premieres.  Through most of the Soviet era, it was known as the Kirov Theatre.  Today, the Mariinsky Theatre is home to the Mariinsky Ballet, Mariinsky Opera and Mariinsky Orchestra.  Since Yuri Temirkanov's retirement in 1988, the conductor Valery Gergiev has served as the theatre's general director.
Answer: Anna Netrebko