Have you ever listened to Skydancer by Dark Tranquillity? It was highly original and creative at the time. Before that, mixing such eclectic elments as acoustics, female vocals and male cleans with melodic guitars and death metal was unheard of. Not to mention The Gallery, which is still a benchmark for Gothenburg metal. Projector too, with about half of the vocals sung clean, and mixing depeche mode influences with death metal was very original and unique.