Leopold Kramer was born in 1870 in Prague, then part of Austria. He studied at the Prague Conservatory, and after graduating in about 1890, became Concertmaster of the Gürzenich Orchestra of Cologne, Germany. Kramer was then Concertmaster of the Amsterdam Concertgebouw 1892-1894. Leopold Kramer was also, perhaps just before coming to Chicago, the Concertmaster of the St. Petersburg Philharmonic. In 1897, Leopold Kramer came to Chicago to join Theodore Thomas's Chicago Symphony. In November, 1909, after Theodore Thomas's death (in 1906), with Frederick Stock now Music Director, Kramer became angry at remarks made by Stock. Leopold Kramer then impulsively quit the Orchestra. Kramer quickly regretted his action and tried to retract his resignation, but it was too late. Kramer then moved to the Chicago Grand Opera. Later, Leopold Kramer became Concertmaster of the New York Philharmonic for one season, 1913-1914. As was the practice of European musicians in that era, Kramer returned to Europe during the summer of 1914. Apparently, he was blocked from returning to New York, because of the outbreak of World War 1. Leopold Kramer was replaced at New York Philharmonic as Concertmaster by Maximilian Pilzer. Leopold Kramer was later Concertmaster of the Metropolitan Opera Orchestra for one season, 1922-1923. Established in New York City, Leopold Kramer taught at the Institute for Musical Arts (later renamed Juilliard) 1920-1924. In the summer of 1924, Kramer returned to Prague to teach, where he lived at least until 1936. http://www.stokowski.org/Principal_Musicians_Metropolitan_Opera.htm
Born Ruffo Titta in Pisa (he reversed his forename and surname for the stage), Ruffo was the son of an engineer. He studied voice with several teachers, but basically his vocal method was self-taught. He made his debut in 1898 at the Teatro Constanzi in Rome as the Herald in Wagner's Lohengrin. After a slow start, his career took off in the early 1900s and he quickly achieved international renown. His major debuts were in Buenos Aires (1902), London (1903), Milan (1904), Lisbon (1907), and the Paris Opéra (1911). Ruffo made his American debut in Philadelphia in 1912 and sang extensively in Chicago. He reached the Metropolitan Opera relatively late in his career, in 1922 as Figaro in The Barber of Seville. He sang 46 performances at the Met from 1922 through 1929. He enlisted during World War I. http://en.wikipedia.org/wiki/Titta_Ruffo