The Slovak Radio Symphony Orchestra, in Slovak Symfonický orchester Slovenského rozhlasu, or SOSR, was the first professional orchestra established in what is now the country of Slovakia. It remains one of the country's most prominent ensembles, and its recordings for Western labels have propelled it to international fame. The Slovak Radio Symphony Orchestra was established in 1929 to serve the needs of the new Slovak Radio network. Its first conductor was Frantisek Dyk. Another key figure during the orchestra's early years was composer Alexander Moyzes, a champion of Slovak music who, at the time, was teaching at the Music and Drama Academy for Slovakia in Bratislava. Moyzes worked to raise the orchestra's musical level, a process that continued after he joined the faculty at the Bratislava Conservatory in 1941 until he was forced to resign during the Communist takeover of Czechoslovakia in 1948. By that time, the orchestra had begun to attract a line of talented conductors, including Ondrej Lenard (1970-1991), Róbert Stankovský (1991-2001), and its present leader, Peter Valentovic. The orchestra has also welcomed internationally prominent guest conductors including, Charles Mackerras, Neeme Järvi, and Kirk Trevor, as well as such soloists as Anna Netrebko and Boris Berezovsky. The Slovak Radio Symphony Orchestra has toured abroad, performing at the Musikverein in Vienna as well as venues as far afield as Spain and Japan. Its activities also include recording soundtrack music for Slovak films. The orchestra has been perhaps most notable for its recordings, which include the world premiere of Ermanno Wolf-Ferrari's I gioielli della Madonna (The Jewels of the Madonna). The SOSR has recorded extensively, and mostly outside of Slovakia, for the Marco Polo and MMC labels, and most of all for Naxos. The group has continued to specialize in Slovak music, and in 2018 they re-released a cycle (originally made for Marco Polo) of Moyzes' 12 symphonies; two volumes in the cycle were released on Naxos in 2019, with Ladislav Slovak conducting.