diff --git a/README.md b/README.md
index 0d7f6ee39cc54d1ce245df1a4cd74a035db1c125..addeb4dd0646f20e5c3bda3e630fc75760becb21 100644
--- a/README.md
+++ b/README.md
@@ -4,8 +4,7 @@ CssLsd is a Chromium Extension which allows for interactively modifying
 the style of web pages using MIDI messages, Keyboard presses or Audio input
 features.
 
-
-## Setup 
+## Setup
 
 - Download or Clone CssLsd
 - Start Chromium
@@ -13,15 +12,39 @@ features.
 - Click "Load unpacked extension" and select the csslsd folder
 - Now the extension should appear in the menu bar
 
-
 ## Usage
 
-TODO
+You need to use a CSS template, like below to map your audio or MIDI events to some CSS properties.
+
+```css
+body {
+    background-color:rgba(0,0,0,[audio.meter.volume]);
+}
+h1 {
+    opacity: [midi.noteon.C];
+}
+```
 
+### MIDI Variables
 
+- midi
+  - noteon
+    - name (ex: C, D, E, F, G, A, B)
+  - controlchange
+    - name
 
-## Ressources 
+### Audio Variables
+
+- audio
+  - energy
+    - bass
+    - mid
+    - treble
+  - meter
+    - volume
+
+## Ressources
 
 - Chrome extensions : https://developer.chrome.com/docs/extensions/mv3/getstarted/
 - WebMIDI : https://webmidijs.org/
-
+- CSSParser : http://glazman.org/JSCSSP/index.html
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