diff --git a/oregano/TODO.md b/oregano/TODO.md
index 5adb39b..39f53e4 100644
--- a/oregano/TODO.md
+++ b/oregano/TODO.md
@@ -12,7 +12,7 @@
 Oregano will have these concepts/objects:
 
 
-- track: like a "track" in renoise. can have notes, and a list of effects.
+- track: like a "track" in renoise. can have notes and a list of filters
 
 
 - instrument: instrument defenitions or presets, and actual instantiated instruments.
diff --git a/oregano/Tutorial.md b/oregano/Tutorial.md
index 4620328..c92cae3 100644
--- a/oregano/Tutorial.md
+++ b/oregano/Tutorial.md
@@ -40,7 +40,7 @@ The purpose of playing notes on different tracks is we can have different filter
 - Filters: can be added to a track. The order in which they are added matters.
 
 
-## Example
+## Examples
 
 ### 1. Creating an instrument
 
@@ -68,10 +68,50 @@ Now that we have an instrument, we can use it to play notes on a specific track.
     ;; TODO - find a way to turn off a note, or make a note play for a specific time
 
 
-TODO:
-- use an instrument to play a note on a track.
-- add filters to  a track
+### 3. Add filters to a track
+
+You can add filters to a specific track.
+
+    (add-effect track3 (reverb 0.5 0.9))
+
+
+## Functions
+
+
+
+### mouse-x and mouse-y
+
+You can parameters to filters and instruments using the mouse.
+
+    (mouse-x start-value end-value)
+
+For example, if you want to control the cutoff frequency for a filter using the left-right position of the mouse.
+
+    (add-effect track3 (low-pass-filter resonance 
+                                        (mouse-x kr 200 500)))
+
+When the mouse is at the left of the screen, the frequency is 200, when the mouse is at the right, the frequency is 500.
+
+
+
+
+
+---
+
+
+    (definst supersaw
+        (
+
+
+
+
+
+
+
+
+
+
+
 
 
-    (append-effect track3 (reverb-effect 0.5 0.9))
 
diff --git a/oregano/routing.rkt b/oregano/routing.rkt
index a225de5..322c804 100644
--- a/oregano/routing.rkt
+++ b/oregano/routing.rkt
@@ -43,6 +43,7 @@ tracks:
 (append-effect 3 'reverb)
 (append-effect 3 'echo)
 
+
 ;; creates a ugen that is routed
 ;; in-bus: input bus channel
 ;; out-bus: output bus channel
@@ -56,12 +57,12 @@ tracks:
                             (mouse-y kr 0 1 0 0.1)
                             0.5)))
 
+;; internal function
 #;(define (make-freeverb-with-in-out in-bus out-bus)
   (out out-bus (free-verb (in 1 ar in-bus) 0.5
                           (mouse-y kr 0 1 0 0.1)
                           0.5)))
 
-;;(define freeverb-effect make-freeverb-with-in-out)