[SOLVED] was able to figure this one out myself.
If you want to start playing a sound on one scene and seamlessly let it continue after the scene change, you can do the following:
Scene 1 call the sound
Scene 2 to continue sound to this scene, play it again from inside the "at the start of the scene" -action
If scene 2 is place you visit otherwise too and you don't want to play the sound every time that scene begins you can put the sound inside a if-sentence, bit like this:
Change "just play once" to true right before you change into scene 2 when sound needs to continue.
if just play once is true
play sound
just play once = false
end if
