@RapidEdwin08 Hell yeah! Glad to see this is still going. Thanks for the update!

@retropie start with a specific % volume

mpg123 -f "32768" # Volume % "100"
mpg123 -f "29484" # Volume % "90 "
mpg123 -f "26208" # Volume % "80 "
mpg123 -f "22932" # Volume % "70 "
mpg123 -f "19656" # Volume % "60 "
mpg123 -f "16380" # Volume % "50 "
mpg123 -f "13104" # Volume % "40 "
mpg123 -f "9828" # Volume % "30 "
mpg123 -f "6552" # Volume % "20 "
mpg123 -f "3276" # Volume % "10 "
mpg123 -f "1638" # Volume % "5 "

@hooperre dont know if it works with ports, my retropie version is latest 4.5.1 latest setup-script and runs on linux Xubuntu 18.04LTS.
btw, this is exact how it worked on my linux pc
its exact what i did to get music in the menus,
maybe do not forget to install mpg123 from synaptic package manager

@cyperghost It's a solid soundtrack mate, I love it, I stumbled upon it ages ago when going through my PlayStation games on discs, almost made for BGM on Emulationstation :)