The first line means that either a relationship or opportunity wasn't destined to happen. We use "It wasn't meant to be" mostly when a relationship doesn't work out. The second line most likely is expressing that the artist doesn't want to be told what to do anymore and isn't going to listen to orders.

The first one I get it as a : "It wasn't supposed to be " meant works as a synonym for supposed and it has a lot of meanings. The second one : I got confused with this one... on one side there is (getting old - ) but the "over" doesn't fit in my mind ! so It would be good if someone else can help us with this