E9 Pedal Steel and D 13b9
No bar on the E9 neck's open strings spells D 13b9.
D 13b9 spells D – D# – F# – A – B – C, and with no pedal or lever down no straight bar or short slant on the E9 neck lands on its tones: at every fret the strings that sound leave one out, or too few of them ring.
The pedals and knee levers are what change that — each one retunes a string under the bar — and this chair's key pages draw them where a country song needs them, every chord change of a called change as a pedal move. This page charts the open strings only, and draws no grip a steel cannot hold.