diff --git a/Karplus_Strong/Karplus_Strong.ino b/Karplus_Strong/Karplus_Strong.ino
index 6de9abc..a5d7136 100644
--- a/Karplus_Strong/Karplus_Strong.ino
+++ b/Karplus_Strong/Karplus_Strong.ino
@@ -1,6 +1,7 @@
-//waveform generator
+// Very basic Karplus-Strong 
+
+// based on this explanation http://sites.music.columbia.edu/cmc/MusicAndComputers/chapter4/04_09.php
 
-// hacked from https://www.instructables.com/Arduino-Waveform-Generator-1/
 
 #include <Adafruit_MCP4728.h>
 #include <Wire.h>