diff --git a/music-pitch-literal.cabal b/music-pitch-literal.cabal
--- a/music-pitch-literal.cabal
+++ b/music-pitch-literal.cabal
@@ -1,6 +1,6 @@
 
 name:                   music-pitch-literal
-version:                1.7.1
+version:                1.7.2
 author:                 Hans Hoglund
 maintainer:             Hans Hoglund
 license:                BSD3
diff --git a/src/Music/Pitch/Alterable.hs b/src/Music/Pitch/Alterable.hs
--- a/src/Music/Pitch/Alterable.hs
+++ b/src/Music/Pitch/Alterable.hs
@@ -16,6 +16,7 @@
 module Music.Pitch.Alterable (
         -- * Alterable class
         Alterable(..),
+        alter,
   ) where
 
 import Data.Ratio
@@ -62,3 +63,17 @@
 instance Alterable a => Alterable (b, a) where
     sharpen = fmap sharpen
     flatten = fmap flatten
+
+{-
+sharpened :: Alterable a => Iso' a a
+sharpened = iso sharpen flatten
+
+flattened :: Alterable a => Iso' a a
+flattened = iso flatten sharpen
+-}
+
+alter :: Alterable a => Int -> a -> a
+alter n x
+  | n < 0  = iterate flatten x !! n
+  | n == 0 = x
+  | n > 0  = iterate sharpen x !! n
diff --git a/src/Music/Pitch/Augmentable.hs b/src/Music/Pitch/Augmentable.hs
--- a/src/Music/Pitch/Augmentable.hs
+++ b/src/Music/Pitch/Augmentable.hs
@@ -16,6 +16,7 @@
 module Music.Pitch.Augmentable (
         -- * Augmentable class
         Augmentable(..),
+        augmentN,
   ) where
 
 import Data.Ratio
@@ -59,3 +60,13 @@
     augment = fmap augment
     diminish = fmap diminish
 
+{-
+augmented :: Augmentable a => Iso' a a
+augmented = iso augment diminish
+-}
+
+augmentN :: Augmentable a => Int -> a -> a
+augmentN n x
+  | n < 0  = iterate diminish x !! n
+  | n == 0 = x
+  | n > 0  = iterate augment x !! n
diff --git a/src/Music/Pitch/Literal/Interval.hs b/src/Music/Pitch/Literal/Interval.hs
--- a/src/Music/Pitch/Literal/Interval.hs
+++ b/src/Music/Pitch/Literal/Interval.hs
@@ -17,9 +17,13 @@
 
 module Music.Pitch.Literal.Interval (
 
+        -- * IsInterval class
         IsInterval(..),
         IntervalL(..),
 
+        -- * Literal values
+        
+        -- ** Simple intervals
         d1,  _P1,  _A1,
         d2,   m2,  _M2,  _A2,
         d3,   m3,  _M3,  _A3,
@@ -28,6 +32,7 @@
         d6,   m6,  _M6,  _A6,
         d7,   m7,  _M7,  _A7,
 
+        -- ** One-octave compounds
         d8,  _P8,  _A8,
         d9,   m9,  _M9,  _A9,
         d10,  m10, _M10, _A10,
@@ -36,12 +41,16 @@
         d13,  m13, _M13, _A13,
         d14,  m14, _M14, _A14,
 
+        -- ** Two-octave compounds
         d15, _P15,  _A15,
 
   ) where
 
-import Data.Semigroup
-import Control.Applicative
+import           Control.Applicative
+import           Data.Fixed
+import           Data.Ratio
+import           Data.Semigroup
+import           Data.Word
 
 newtype IntervalL = IntervalL (Integer, Integer, Integer)
 -- (octaves, diatonic steps, chromatic steps)
@@ -66,6 +75,21 @@
 
 instance (Monoid b, IsInterval a) => IsInterval (b, a) where
     fromInterval = pure . fromInterval
+
+instance IsInterval Int where
+    fromInterval x = fromIntegral (fromInterval x :: Integer)
+
+instance IsInterval Word where
+    fromInterval x = fromIntegral (fromInterval x :: Integer)
+
+instance IsInterval Float where
+    fromInterval x = realToFrac (fromInterval x :: Double)
+
+instance HasResolution a => IsInterval (Fixed a) where
+    fromInterval x = realToFrac (fromInterval x :: Double)
+
+instance Integral a => IsInterval (Ratio a) where
+    fromInterval x = realToFrac (fromInterval x :: Double)
 
 instance IsInterval Double where
     fromInterval = fromIntegral . asInteger . fromInterval
diff --git a/src/Music/Pitch/Literal/Pitch.hs b/src/Music/Pitch/Literal/Pitch.hs
--- a/src/Music/Pitch/Literal/Pitch.hs
+++ b/src/Music/Pitch/Literal/Pitch.hs
@@ -17,33 +17,45 @@
 
 module Music.Pitch.Literal.Pitch (
 
+        -- * IsPitch class
         IsPitch(..),
         PitchL(..),
-
+        
+        -- * Literal values
+        
+        -- ** Two octaves up
         cs'', ds'', es'', fs'', gs'', as'', bs'',
         c'' , d'' , e'' , f'' , g'' , a'' , b'' ,
         cb'', db'', eb'', fb'', gb'', ab'', bb'',
 
+        -- ** One octave up
         cs' , ds' , es' , fs' , gs' , as' , bs' ,
         c'  , d'  , e'  , f'  , g'  , a'  , b'  ,
         cb' , db' , eb' , fb' , gb' , ab' , bb' ,
 
+        -- ** Standard octave
         cs  , ds  , es  , fs  , gs  , as  , bs  ,
         c   , d   , e   , f   , g   , a   , b   ,
         cb  , db  , eb  , fb  , gb  , ab  , bb  ,
 
+        -- ** One octave down
         cs_ , ds_ , es_ , fs_ , gs_ , as_ , bs_ ,
         c_  , d_  , e_  , f_  , g_  , a_  , b_  ,
         cb_ , db_ , eb_ , fb_ , gb_ , ab_ , bb_ ,
 
+        -- ** Two octaves down
         cs__, ds__, es__, fs__, gs__, as__, bs__,
         c__ , d__ , e__ , f__ , g__ , a__ , b__ ,
         cb__, db__, eb__, fb__, gb__, ab__, bb__
 
   ) where
 
-import Data.Semigroup
-import Control.Applicative
+import           Control.Applicative
+import           Data.Fixed
+import           Data.Int
+import           Data.Ratio
+import           Data.Semigroup
+import           Data.Word
 
 -- Pitch literal, defined as @(class, alteration, octave)@, where
 --
@@ -51,11 +63,11 @@
 --
 --     * @alteration@ is the number of semitones, i.e. 0 is natural, 1 for sharp 2 for double sharp, -1 for flat and -2 for double flat.
 --       Alteration is in 'Maybe' because some pitch representations differ between explicit and explicit accidentals, i.e. a diatonic
---       pitch type may assume @(0,Nothing,4)@ to mean C sharp rather than C.
+--       pitch type may assume @(0,Nothing,...)@ to mean C sharp rather than C.
 --
 --     * @octave@     is octave number in scientific pitch notation.
 --
--- Middle C is represented by the pitch literal @(0, Nothing, 4)@.
+-- Middle C is represented by the pitch literal @(0, Nothing, 0)@.
 --
 newtype PitchL = PitchL { getPitchL :: (Int, Maybe Double, Int) }
     deriving (Eq, Show, Ord)
@@ -80,6 +92,21 @@
 
 instance (Monoid b, IsPitch a) => IsPitch (b, a) where
     fromPitch = pure . fromPitch
+
+instance IsPitch Int where
+    fromPitch x = fromIntegral (fromPitch x :: Integer)
+
+instance IsPitch Word where
+    fromPitch x = fromIntegral (fromPitch x :: Integer)
+
+instance IsPitch Float where
+    fromPitch x = realToFrac (fromPitch x :: Double)
+
+instance HasResolution a => IsPitch (Fixed a) where
+    fromPitch x = realToFrac (fromPitch x :: Double)
+
+instance Integral a => IsPitch (Ratio a) where
+    fromPitch x = realToFrac (fromPitch x :: Double)
 
 instance IsPitch Double where
     fromPitch (PitchL (pc, sem, oct)) = fromIntegral $ semitones sem + diatonic pc + oct * 12