diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -246,3 +246,7 @@
 ## 0.24.6.0 -- 2020-04-07
 
 * Twenty-fourth version revised F. Fixed issue with being not compiled.
+
+## 0.25.0.0 -- 2020-04-09
+
+* Twenty-fifth version. Added more possibilities to edit function f from the DobutokO.Sound.Functional module. 
diff --git a/DobutokO/Sound/Functional.hs b/DobutokO/Sound/Functional.hs
--- a/DobutokO/Sound/Functional.hs
+++ b/DobutokO/Sound/Functional.hs
@@ -100,6 +100,16 @@
   , maybeFFromStrVec
   , fVecCoefs
   , showFFromStrVec
+  -- * Functions to edit 'OvertonesO' and function f (since 0.25.0.0)
+  , renormF
+  , renormFD
+  , sameOvertone
+  , sameOvertoneL  
+  , sameFreqF
+  , sameFreqFI
+  , fAddFElem
+  , fRemoveFElem
+  , gAdd01
 ) where
 
 import Text.Read (readMaybe)
@@ -984,3 +994,67 @@
         l = length ("(" ++ (showFFloat Nothing y "") ++ ",(\t -> <(" ++ concat (V.toList . V.map (\z -> (showFFloat Nothing (fst z) $
               " * t, " ++ (showFFloat Nothing (snd z) $ "),("))) $ (f 1))) in take (l - 2) ("(" ++ (showFFloat Nothing y "") ++ ",(\t -> <("
                 ++ concat (V.toList . V.map (\z -> (showFFloat Nothing (fst z) $ " * t, " ++ (showFFloat Nothing (snd z) $ "),("))) $ (f 1))) ++ ">))"
+
+----------------------------------------------------------------------------------------
+
+-- | Renormalizes amplitudes for the frequencies so that the maximum one of them (if 'OvertonesO' is not 'V.empty') is equal by the absolute value
+-- to 1.0 and the mutual ratios of the amplitudes are preserved.
+renormF :: OvertonesO -> OvertonesO
+renormF v
+ | V.null v = V.empty
+ | otherwise =
+    let v1 = V.fromList . sortBy (\(x1,y1) (x2,y2)-> compare (abs y2) (abs y1)) . V.toList $ v in
+      V.map (\(x,y) -> (x, y / (snd . V.unsafeIndex v1 $ 0))) v1
+
+-- | Renormalizes amplitudes for the frequencies so that the maximum one of them (if 'OvertonesO' is not 'V.empty') is equal by the absolute value
+-- to 'Double' argument and the mutual ratios of the amplitudes are preserved.
+renormFD :: Double -> OvertonesO -> OvertonesO
+renormFD ampl0 v
+ | V.null v = V.empty
+ | otherwise =
+    let v1 = V.fromList . sortBy (\(x1,y1) (x2,y2)-> compare (abs y2) (abs y1)) . V.toList $ v in
+      V.map (\(x,y) -> (x, ampl0 * y / (snd . V.unsafeIndex v1 $ 0))) v1      
+
+-- | Predicate to check whether all tuples in a 'V.Vector' have the same first element.
+sameOvertone :: OvertonesO -> Bool
+sameOvertone v
+ | V.null v = False
+ | otherwise = V.all (\(x,_) -> x == (fst . V.unsafeIndex v $ 0)) v
+
+-- | Similar to 'sameOvertone', except that not the 'V.Vector' is checked but a corresponding list.
+sameOvertoneL :: [(Double,Double)] -> Bool
+sameOvertoneL xs@((x,y):_) = all (\(xn,_) -> xn == x) xs
+sameOvertoneL _ = False
+
+-- | @g :: (Double,Double) -> OvertonesO -> OvertonesO@ is a function that defines how the new element is added to the 'OvertonesO'.
+sameFreqF :: Double -> (Double,Double) -> (Double -> OvertonesO) -> ((Double,Double) -> OvertonesO -> OvertonesO) -> OvertonesO
+sameFreqF freq (noteN0,amplN0) f g = g (noteN0,amplN0) (f freq)
+
+-- | @g :: (Double,Double) -> OvertonesO -> OvertonesO@ is a function that defines how the new element is added to the 'OvertonesO'.
+-- Variant of 'sameFreqF' where g depends only on the elements of the 'OvertonesO', which first elements in the tuples equal to the first element
+-- in the @(Double,Double)@.
+sameFreqFI :: Double -> (Double,Double) -> (Double -> OvertonesO) -> ((Double,Double) -> OvertonesO -> OvertonesO) -> OvertonesO
+sameFreqFI freq (noteN0,amplN0) f g = g (noteN0,amplN0) . V.filter (\(x,y) -> x == noteN0) $ f freq
+
+-- | @gAdd :: (Double,Double) -> Double -> (Double -> OvertonesO) -> OvertonesO@ is a function that defines how the element is added
+-- to the 'OvertonesO'.
+fAddFElem :: (Double, Double) -> Double -> (Double -> OvertonesO) -> ((Double,Double) -> Double -> (Double -> OvertonesO) -> OvertonesO) ->
+  (Double -> OvertonesO)
+fAddFElem (noteN,amplN) freq f gAdd = \t -> gAdd (noteN,amplN) t f
+
+-- | @gRem:: (Double,Double) -> Double -> (Double -> OvertonesO) -> OvertonesO@ is a function that defines how the element is removed
+-- from the 'OvertonesO'.
+fRemoveFElem :: (Double, Double) -> Double -> (Double -> OvertonesO) -> ((Double,Double) -> Double -> (Double -> OvertonesO) -> OvertonesO) ->
+  (Double -> OvertonesO)
+fRemoveFElem (noteN,amplN) freq f gRem = \t -> gRem (noteN,amplN) t f
+
+-- | Example of the function gAdd for the 'fAddFElem'. If the frequency is already in the 'OvertonesO' then the corresponding amplitude is divided
+-- equally between all the elements with the repeated given frequency from @(Double, Double)@. Otherwise, it is just concatenated to the 'OvertonesO'.
+gAdd01 :: (Double,Double) -> Double -> (Double -> OvertonesO) -> OvertonesO
+gAdd01 (note,ampl) freq f 
+ | V.null . f $ freq = V.singleton (note,ampl)
+ | otherwise =
+    let v1 = renormF . f $ freq in
+     let v2 = V.findIndices (\(x,_) -> x == note) $ v1 in
+       if V.null v2 then V.cons (note,ampl) (f freq)
+       else renormF . V.imap (\i (t,w) -> if i `V.elem` v2 then (t,w + ampl / fromIntegral (V.length v2)) else (t,w)) $ v1
diff --git a/dobutokO2.cabal b/dobutokO2.cabal
--- a/dobutokO2.cabal
+++ b/dobutokO2.cabal
@@ -2,7 +2,7 @@
 -- documentation, see http://haskell.org/cabal/users-guide/
 
 name:                dobutokO2
-version:             0.24.6.0
+version:             0.25.0.0
 synopsis:            A program and a library to create experimental music from a mono audio and a Ukrainian text
 description:         It can also create a timbre for the notes. Uses SoX inside.
 homepage:            https://hackage.haskell.org/package/dobutokO2