One of the trademarks of the Pain of Salvation sound is their ability to create complex multi-part vocal arrangements. You can hear this on such tracks as "Water" and "Waking Every God". Most metal bands don't seem to concentrate on this area of their music. They can create great music and a great vocal part... but they don't worry about enhancing the vocals with additional secondary vocal parts... I am not talking about backing vocals for the chorus... but multiple simultaneous vocal parts... I think more concentration on this neglected area of music could enhance metal. It is creative and adds an extra, deeper element to the music...