Complex sentence: The last concert that would have played at the stadium was a Bruce Springsteen concert in 2003; however, it was canceled, due to low ticket sales and moved to the smaller Darien Lake Performing Arts Center instead.
Split into simpler sentences: The last concert that would have played at the stadium was a Bruce Springsteen concert in 2003. That concert was canceled due to low ticket sales and moved to the smaller Darien Lake Performing Arts Center instead.