diff --git a/notes.md b/notes.md
index a891d7f..1a43459 100644
--- a/notes.md
+++ b/notes.md
@@ -63,3 +63,6 @@
 - since we don't know if we can even get the shift registers on time,
   it's possible to make our own via another Arduino that has all the buttons
   connected to it and it sends the data over USART to the speaker Arduino
+- the length of each note can be saved as how many cycles of the square
+  wave note were generated, perhaps with a prescalar if it's a really long
+  and high frequency note