Simplify the following text for a Grade 10 native English-speaking person.
Original: His first important conducting job was with the Dresden Philharmonic Orchestra with whom he worked from 1955 â `` 1958 and again from 1967 to 1972 .
Simplified: Masur conducted the Dresden Philharmonic Orchestra for three years ending in 1958 and again from 1967 to 1972 .