Complex sentence: The Heads or skins consist of a batter head, which forms the playing surface on the top of the drum and a resonant head on the bottom, the resonant head is usually much thinner than the batter head and as such is not beaten while playing.
Split into simpler sentences: The Heads or skins consist of a batter head, which forms the playing surface on the top of the drum and a resonant head on the bottom. The resonant head is usually much thinner than the batter head and is not beaten while playing.