Complex sentence: In 1973, Secretary of State Henry Kissinger's birthday party was held at the Colony Club; among the guests were four couples whom Kissinger had ordered to be wiretapped, and in 2007, memorial services for Brooke Astor were held there.
Split into simpler sentences: In 1973, Secretary of State Henry Kissinger's birthday party was held at the Colony Club (among the guests, ironically, were four couples whom Kissinger had ordered to wiretapped). In 2007, memorial services for Brooke Astor were held there.