Wikipedia
Copedent is a table used to describe the tuning and pedal arrangement on a pedal steel guitar. The term was coined by Tom Bradshaw in an early 1970s article in Guitar Player magazine. It is short for "ChOrd PEDal arrangemENT". According to Bradshaw, the term is pronounced "co-PEE-dent". A complete copedent includes string gauges, and whether a string is plain or wound. A complete copedent also indicates the degree to which a string is altered, using "+" to indicate a half-step raise, and "-" to indicate a half-step lower.
A standard E9 single-neck pedal steel guitar's copedent is charted below. Pedal steel players who play country music most often use an E9th tuning. The particular copedent first listed below is commonly referred to as an "Emmons set-up." Another common copedent, the "Day set-up," is almost identical, except that the functions of Pedal 1 and Pedal 3 are reversed. These two copedents are named for Pedal steel pioneers "Buddy Emmons" and "Jimmy Day" respectively. The "Emmons" set-up is by far the most popular being found on 9 out of 10 steel guitars, and most manufacturers ship their new pedal steels to dealers with the "Emmons" copedent. Another common copedent utilizes the C6th tuning. Most steelers use one or both of these two copedents. However, many steelers create their own unique copedents.
String
Gauge
Pitch
P1
P2
P3
LKL
V
LKR
RKL
RKR
1
.012p
F#
-
-
-
-
-
-
++G#
-
2
.015p
D#
-
-
-
-
-
-
+E
-D/--C#
3
.011p
G#
-
+A
-
-
-
-
-
-
4
.014p
E
-
-
++F#
+F
-
-D#
-
-
5
.018p
B
++C#
-
++C#
-
---A#
-
-
-
6
.022p
G#
-
+A
-
-
-
-
--F#
-
7
.026w
F#
-
-
-
-
-
-
-
-
8
.030w
E
-
-
-
+F
-
-D#
-
-
9
.034w
D
-
-
-
-
-
-
-
-C#
10
.038w
B
++C#
-
-
-
---A#
-
-
-
Most pedal steel guitarists play steel guitars with two necks. These instruments use the E9 copedent shown above on the neck farther away from the player. The neck nearer to the player is tuned to C6, and five more pedals change the pitches of the strings on this neck, as shown below. Steel guitarists use the C6 neck for playing in a jazz or Western Swing idiom. The tuning makes it easier to play the more complex chord voicings commonly associated with these kinds of music, and the heavier strings contribute a "thicker" or "fatter" tone.
String
Gauge
Pitch
P1
P2
P3
P4
P5
P6
P7
P8
LKL
V
LKR
RKL
RKR
1
.012p
G
-
-
-
-
+G#
-
-
-
-
-
-
-
-
2
.014p
E
-
-
-
-
-
+F
-
-
-
-
-
-
-
3
.017p
C
-
-
-
-
-
-
++D
-
-
-
-
-B
+C#
4
.020p
A
-
-
-
++B
-
-
++B
-
-Ab
-
+Bb
-
-
5
.024w
G
-
-
-
-
-F#
-
-
-
-
-
-
-
-
6
.030w
E
-
-
-
-
-
-Eb
-
-
-
-
-
-
-
7
.036w
C
-
-
-
-
-
-
-
+C#
-
-
-
-
-
8
.042w
A
-
-
-
++B
-
-
-
-
-
-
-
-
-
9
.054w
F
-
-
-
-
+F#
-
-
-E
-
-
-
-
-
10
.070w
C
-
-
-
-
++D
-
-
---A
-
-
-
-
-
Pedal steelers refer to Pedal 8 as the "boo-wah", the "doo-wah",the "splat" pedal or the "ba-room"(bar-room)pedal, because of the sound the low C string makes when it drops the minor third to A.
In an effort to combine the advantages of each tuning into a single-neck instrument, Jeff Newman (now deceased) developed a 12-string "universal tuning" in the mid 1970s using the E9th as the basic tuning. At approximately the same time, Maurice Anderson developed a 12-string "universal tuning", but the basic tuning was a Bb6th. Both steelers publicized their efforts, with the E9th "universal tuning" being the most common employed today by those preferring to use a "universal tuning."
String
Gauge
Pitch
P1
P2
P3
P4
P5
P6
P7
P8
LKL
V
LKR
RKL
RKR
1
.013p
F#
-
-
-
-
+G
-
-
-
-
+G
-
-
-
2
.015p
D#
-
-
-
-
-
-
-
-
-
-
-
-
-D
3
.011p
G#
-
+A
-
-
-
-
-
-
-
-
-
-
-
4
.014p
E
-
-
++F#
-
-
+E
-
-
+F
-
-Eb
-
-
5
.018p
B
++C#
-
++C#
-
-
-
++C#
-
-
-
-
-Bb
-
6
.022w
G#
-
+A
-
++A#
-
-
++A#
-
-
-
-
-
-
7
.026w
F#
-
-
-
-
-F
-
-
-
-
+G
-
-
-
8
.030w
E
-
-
-
-
-
--D
-
-
+F
-
-Eb
-
-
9
.038w
B
++C#
-
-
-
-
-
-
+C
-
-
-
-Bb
+++D
10
.046w
G#
-
+A
-
++A#
-
-
-
-
-
-
-
-
-
11
.056w
E
-
-
-
-
+F
-
-
-D#
-
-
-
-
-
12
.068w
B
-
-
-
-
++C#
-
-
---G#
-
-
-
-
-
The universal copedent is the one with the most variations from player to player.