Yes, as I said it is working in a way. It's not in the way you think.
You can only prolong the music of p/b
If raid have p/b so every member can use enhanced music. So if someone w/m play music he got 18% from tamb(example). That was idea.
Yes. And it is in a way like that:
If p/b play tamb, you get as w/m 18% dmg. If you play tamb BEFORE the music of p/b is over, you have a 30 sec fresh tamb + 3% extra buff, which results in the benefit near like 18% tamb