Complex sentence: The stadium's original capacity of 35,000 for a concert has to be expanded to 38,000 to accommodate additional ticket demands, making Janet the only artist in the stadium's history to fill the venue over its intended capacity.
Split into simpler sentences: The stadium's original capacity of 35,000 for a concert has to be expanded to 38,000 to accommodate additional ticket demands. This made Janet the only artist in the stadium's history to fill the venue over its intended capacity.