E9 tuning

E9 tuning (also E9 chromatic tuning) is a common tuning for steel guitar necks of more than six strings. The name derives from the chord spelled by the tuning.

The practice evolved from 1950s–1970s through the work of musicians like Bud Isaacs, Ralph Mooney, and Buddy Emmons. It supports optimal chord and scale patterns across a single position on the 10-string pedal steel guitar.