I'm sure people have thought of this before, but I decided to make my own version, which I call Canticode, from the Latin word for song (canticum). It's not necessarily a secure way of sending information, rather it's a way of interpreting certain frequencies as letters which correspond to a note. Attached is a link to the text file and an example that says the word "hello world".
As of this moment, I'm just making a simple program to automate the process of encoding words into the code. If any lains have suggestions on improvement or code of your own to decode it, it would be very interesting.
https://pastebin.com/BS7v27cu
http://www.yourfilelink.com/get.php?fid=2041826