Complex sentence: It served as a venue for rock concerts in the 1970s, and in 1985 became the Palladium nightclub, designed by Arata Isozaki.
Split into simpler sentences: It served as a venue for rock concerts in the 1970s, changing its name to the Palladium. In 1985 the theater closed for concerts and became the Palladium nightclub, designed by Arata Isozaki.