No, Sabbath introduced a completely new sound as well, their style of slow droning chords had never been to used the same extreme before they did. On the first album there was a still a heavy blues influence, but then you get tracks like Black Sabbath, War Pigs, Electoric funeral, and into the Void, all with much louder guitars than bands before, and a much more droning morbid feel to them, and thats without even mentionning the lyrics.