The National University, Universidad Nacional, has a resident string quartet and a symphony orchestra, which had its very successful premiere at the National Theatre in San José on May 10, 2007, conducted by Dieter Lehnhoff. It has also a highly successful piano school led by the Russian virtuoso, Alexandr Sklioutovsky. Other well-known groups are the El Café Chorale and the Sura Chamber Choirand also the pianist Ismael Pacheco, who was the second Costa Rican pianist to have been performed at the prestigious Carnegie Hall in 2001 and also at the Musikverein in 2007 [http://www.myspace.com/izmaelpacheco.