Complex sentence: For three years, Järvi worked as assistant conductor of the Los Angeles Philharmonic before being appointed as principal conductor of the Norrlands Opera Symphony Orchestra of Umeå in Sweden for four years.
Split into simpler sentences: For three years, Järvi worked as assistant conductor of the Los Angeles Philharmonic. He then became principal conductor of the Norrlands Opera Symphony Orchestra of Umeå in Sweden for four years.