Update Tutorial.md

oregano/Tutorial.md

@@ -46,6 +46,7 @@ The purpose of playing notes on different tracks is we can have different filter
 
 You can either use a preset instrument or define your own instrument
 
+```clj
 ;; this uses the piano preset
 (define my-piano (preset-instrument 'piano))
 
@@ -57,6 +58,7 @@ You can either use a preset instrument or define your own instrument
 ;; add envelope to instrument
 (define my-inst (preset-instrument "sine"
     (envelope A S D R))
+```
 
 ### 2. Playing a note