She soon began to sing leading parts , and in 1943 she sang the part of Eva in Wagner 's Die Meistersinger von NÃ 1\/4 rnberg at the Vienna State Opera conducted by Karl BÃ hm . She began to sing the leading parts in 1942 by singing the part of Agathe in Weber 's Der FreischÃ 1\/4 tz in 1942 , and the next year she made her debut at Vienna State Opera by singing the part of Eva in Wagner 's Die Meistersinger von NÃ 1\/4 rnberg conducted by Karl BÃ hm .