Complex sentence: They flew to the UK on 17 September 1976 to play a show in London's Hyde Park supporting Queen, and then they opened shows in the rest of Europe for the Hollies during September and October.
Split into simpler sentences: They flew to the UK on 17 September 1976 to play a show in London's Hyde Park supporting Queen. They then opened shows in the rest of Europe for the Hollies during September and October.