The songs are (the number is the key to press to get that song) 1 - Rock and Roll || Led Zeppelin 2 - Immigrant Song || Led Zeppelin 3 - Back in Black || AC/DC 4 - Thunderstruck || AC/DC The pause button will pause the song playing (I believe I got the pausing code from @griffpatch). Other than the pausing code, all has been coded by me. In order to switch songs you have to first repress the green flag first.
