Original sentence: It was formed in January 2001 by four performing artists - Matt Constain, Abigail Yeates, Corrine Pierre and Sean Kempton, all of which had performed in the Millennium Dome Show, which was part of the ‘Millennium Experience’
Edited sentence: It was formed in January 2001 by four performing artists - Matt Constain, Abigail Yeates, Corinne Pierre and Sean Kempton, all of which had performed in the Millennium Dome Show, which was part of the ‘Millennium Experience’