Complex sentence: The Mareham le Fen Victory Silver Band provides the music for a service which commemorates the over 250 villages and hamlets lost in Lincolnshire over the past four centuries.
Split into simpler sentences: The Mareham Le Fen Victory Silver Band provides the music for the service. The service commemorates the historical fact that over 250 villages and hamlets have been lost in Lincolnshire over the past four centuries.