After the war , fortunes recovered under the music directors Hans Rosbaud and Rudolf Kempe and in 1979 , Sergiu Celibidache took over , raising the orchestra to the highest world - class standards .
After the war fortunes recovered under the music directors Hans Rosbaud and Rudolf Kempe . 
 In 1979 , Sergiu Celibidache took over , raising the orchestra to the highest world - class standards .