About Nader Mashayekhi Nader Mashayekhi (Persian: نادر مشایخی) (born November 26, 1958 in Tehran) is a Persian avant-garde composer. Since 2006 until July 2007 he was conductor of Tehran Symphony Orchestra. In 1990s he was music director of an Austrian new music ensemble named "Wien 2001". Nader Mashayekhi studied at University of Music in Vienna and his teacher was Roman Haubenstock-Ramati. Some of his Works have been performed by Radio Symphony Orchestra, Vienna (1998), Ensemble Zwischen Töne, Berlin (1997-98-99-2000), Klangforum Wien (1992-95), Ensemble Work in Progress, Berlin (1993), Savarian Symphony Orchestra (1997) and Tehran Symphony Orchestra (1998-2000). The 2007 Vein modern festival was allocated to him and some of his works were performed there like "Ishango bones". The Ishango bones was discovered in 60's decade in Africa, it had engravings at its forth surface, these engravings were the prime numbers between 10 and 20 (11, 13, 17, 19). Mashayekhi composed a piece which was inspired from it and based on the prime numbers. Frank Scheffer, Dutch cinematographer and producer of documentary film, (mostly known for his works Five Orchestral Pieces (1994), Conducting Mahler (1995), Frank Zappa: Phase II - The Big Note (2002)) made a documentary on Nader Mashayekhi’s life.