Most of us horn players were taught to play F horn up to written G then Bb side on up. Since I use Bb marching horns in HS, teaching Bb fingerings from day one with beginners is ideal (since we are lucky enough to have double horns for everyone). Projection, are you kidding? When did you ever get enough....horn in your band? Bb horn side will get them heard! Just do not put them on the outside left. Please!