diff --git a/src/TabCode/Parser.hs b/src/TabCode/Parser.hs
index 9026348..42b7ba9 100644
--- a/src/TabCode/Parser.hs
+++ b/src/TabCode/Parser.hs
@@ -240,7 +240,7 @@ trebNote = do
 
 fret :: GenParser Char st Fret
 fret = do
-  f <- oneOf ['a'..'n']
+  f <- oneOf "abcdefghiklmnopqrstvwxyz"
   return $ case f of
     'a' -> A
     'b' -> B
@@ -251,11 +251,21 @@ fret = do
     'g' -> G
     'h' -> H
     'i' -> I
-    'j' -> J
     'k' -> K
     'l' -> L
     'm' -> M
     'n' -> N
+    'o' -> O
+    'p' -> P
+    'q' -> Q
+    'r' -> R
+    's' -> S
+    't' -> T
+    'v' -> V
+    'w' -> W
+    'x' -> X
+    'y' -> Y
+    'z' -> Z
     _   -> error $ "Invalid fret symbol: " ++ (show f)
 
 course :: GenParser Char st Course
@@ -392,7 +402,7 @@ ornament = option Nothing $ (try abbr) <|> (try full)
     full = do
       between (char '(') (char ')') $ do
         char 'O'
-        t <- oneOf "abcdefghijklm"
+        t <- oneOf ['a'..'m']
         s <- optionMaybe int
         pos <- option Nothing $ attachment
         return $ Just $ case t of
diff --git a/src/TabCode/Serialiser/MEIXML/Elements.hs b/src/TabCode/Serialiser/MEIXML/Elements.hs
index a94fbcc..51ebc16 100644
--- a/src/TabCode/Serialiser/MEIXML/Elements.hs
+++ b/src/TabCode/Serialiser/MEIXML/Elements.hs
@@ -490,11 +490,21 @@ fretNo F = pack "5"
 fretNo G = pack "6"
 fretNo H = pack "7"
 fretNo I = pack "8"
-fretNo J = pack "9"
-fretNo K = pack "10"
-fretNo L = pack "11"
-fretNo M = pack "12"
-fretNo N = pack "13"
+fretNo K = pack "9"
+fretNo L = pack "10"
+fretNo M = pack "11"
+fretNo N = pack "12"
+fretNo O = pack "13"
+fretNo P = pack "14"
+fretNo Q = pack "15"
+fretNo R = pack "16"
+fretNo S = pack "17"
+fretNo T = pack "18"
+fretNo V = pack "19"
+fretNo W = pack "20"
+fretNo X = pack "21"
+fretNo Y = pack "22"
+fretNo Z = pack "23"
 
 fretGlyphIt :: Fret -> Text
 fretGlyphIt f = fretNo f
@@ -509,11 +519,21 @@ fretGlyphFr F = pack "f"
 fretGlyphFr G = pack "g"
 fretGlyphFr H = pack "h"
 fretGlyphFr I = pack "i"
-fretGlyphFr J = pack "j"
 fretGlyphFr K = pack "k"
 fretGlyphFr L = pack "l"
 fretGlyphFr M = pack "m"
 fretGlyphFr N = pack "n"
+fretGlyphFr O = pack "o"
+fretGlyphFr P = pack "p"
+fretGlyphFr Q = pack "q"
+fretGlyphFr R = pack "r"
+fretGlyphFr S = pack "s"
+fretGlyphFr T = pack "t"
+fretGlyphFr V = pack "v"
+fretGlyphFr W = pack "w"
+fretGlyphFr X = pack "x"
+fretGlyphFr Y = pack "y"
+fretGlyphFr Z = pack "z"
 
 durSymb :: Duration -> Beat -> Dot -> Text
 durSymb Fermata _ Dot = error "Dotted fermata not allowed"
diff --git a/src/TabCode/Types.hs b/src/TabCode/Types.hs
index 144b43e..4f41743 100644
--- a/src/TabCode/Types.hs
+++ b/src/TabCode/Types.hs
@@ -65,7 +65,7 @@ data RhythmSign = RhythmSign Duration Beat Dot (Maybe (Beam Duration)) deriving
 -- FIXME Perhaps this data model should rather be a numeric fret
 -- number and then any symbol from the source should be captured as
 -- another part of the Note type
-data Fret = A | B | C | D | E | F | G | H | I | J | K | L | M | N deriving (Eq, Show, Ord)
+data Fret = A | B | C | D | E | F | G | H | I |  K | L | M | N | O | P | Q | R | S | T | V | W | X | Y | Z deriving (Eq, Show, Ord)
 
 data Course
   = One