John is correct.
This E7th tuning was one of 3 tunings that were the most popular of many tunings that followed the evolution of the Hawaiian guitar after it was invented.
The other 2 were A major with low bass. And C#minor.
E
C#
A
E
A
E
E
C#
G#
E
C#
G#
From these 3, most tunings evoloved into a myriad of over 100 tunings today. Even our beloved PSG!
But of all the tunings ever devised, NONE had the impact among steel players as the one Jerry Byrd invented in the 40's. And that of course is C6.
E
C
A
G
E
C
And in the hands of the master (JB), it can do it all. (Lapsteel of course). On pedal steel, NO tuning ever deivised can do what E9th can. But when you analyze it, it contains "the 3 most popular tunings ever......." 
God bless JB and all of you,
carl[This message was edited by C Dixon on 01 February 2001 at 05:37 AM.]
