Complex sentence: During the 1960s and 1970s, the building's exterior became increasingly dilapidated; among those concerned about the church's deterioration was Russian bard Vladimir Vysotsky, who lived in a house across the street.
Split into simpler sentences: During the 1960s and 1970s, the building's exterior became increasingly dilapidated. Many became concerned about the church's plight including Russian bard Vladimir Vysotsky, who lived in a house across the street.