Sextet was by the Polish composer who has completed how many operas?
Krzysztof Penderecki Krzysztof Eugeniusz Penderecki ( ; ] ; born 23 November 1933) is a Polish composer and conductor. "The Guardian" has called him Poland's greatest living composer. Among his best known works are his "Threnody to the Victims of Hiroshima", "Symphony No. 3", "St. Luke Passion", "Polish Requiem", "Anaklasis", "Utrenja", four operas, eight symphonies and other orchestral pieces, a variety of instrumental concertos, choral settings of mainly religious texts, as well as chamber and instrumental works.
Teresa Żylis-Gara Teresa Żylis-Gara (born 23 January 1935) is a Polish operatic soprano who had a major international career during the 1950s through the 1990s. Although chiefly known for her portrayals in operas by Mozart, Puccini and Verdi, she sang a broad repertoire that encompassed a wide array of musical periods and languages. In addition to her work on the stage, she has been active as a concert singer and recitalist, and is particularly admired for her interpretations of the works of Bach, Handel and Brahms.