Ugh... so silly! Did not have that box ticked. I don't know how it "un-ticked" though. Anyway, all good now. Thanks @Dadais !Get the music option "on" ? (game/game option/"music" box)
Advice from the guy who hardly played music .
You could check if it works by doing (game/pick music).
Otherwise, you can also launch a music using Lua and, per exemple, a onKeyPress.
Please notice that, while sounds are overlapping, only one music is played at a time.