I use now background music in an overlay, works great!
The question from the customer - when a commercial video is played (with sound) within the campaign, how can we make it that the music is surpressed during this commercial?
May be you need to reverse things a little. You can add audio to region or widget, and you can use overlay for the commercial, this way may be the audio will be surpressed
When i put the audio (radio) stream on an region in every layout, the radio keeps starting.