text: Progressive metal ( sometimes known as prog metal ) is a subgenre of heavy metal , which blends the powerful , guitar-driven sound of metal with the complex compositional structures , odd time signatures , and intricate instrumental playing of progressive rock .
simplified: Progressive metal ( often called prog metal ) is a sub-genre of heavy metal music that mixes the powerful , guitar-driven sound of metal with the complexity of progressive rock , which includes odd time signatures and complicated instrumental playing .