Embarrassingly, I was actually accepted to the jazz program at UNT out of high school (not that I was really good or anything, but I was accepted), so I SHOULD know what the hell I'm talking about. Range would make a lot of sense, otherwise you'd be dropping off the bottom of the staff every time to notate something if the purpose of the part is to harmonize in a specific range. I don't actually think before I type after a certain hour.