I've checked my current UK tour production bible and the lowest note Che (that i could see) sings is Bb (2 Below Middle C)and i can't find it in the score (mainly cos i can't be bothered rummaging through it lol) but Che deffo sings a top Bb (1 above middle C) in one of the number - so your lucky at 2 octaves - if i remember (or stumble across) which number it features in i'll update my post. Hope this is some help