I am confused about how to implement music in my code. Is it possible to create your own soundtrack and put it in the game in Codea or do I have to transfer my code into Xcode first?
Music per se isn’t currently supported in Codea, although there is low-level sound support and sound effects. If you want to implement music within your Codea code, the check out my ABC music player. It’s an ugly hack. 
otherwise, you could put some Objective-C code to play a file in your Xcode project. There are some threads in the forum on these options. Good luck!
There is also new David Such’s tutorial about sound:
Tutorial 28 - Codea v1.5.2: Objective C Add On, Audio
http://codeatuts.blogspot.sk/2013/04/tutorial-28-codea-v152-objective-c-add.html
I am not using Xcode yet so I will try the ABC Player but should I copy all the files in github as different projects in Codea, or which file shall I copy so that I can use the ABC Player? Thanks…
I just updated Tutorial 28 to include a sample Codea project which has power level meters for the left and right speakers.