Kesha's Billboard Music Awards performance was about "musical development".

Ben said: "I look at it more as a musical and career development. And I think one of the classiest things about what she did was that it wasn't about drama - it was just about music and just about a beautiful song ...

"What you have with her is perhaps the only one of I've seen of this sort in my life, which is product to artist. And that doesn't disparage her early work because it's fantastic, but it is incredibly produced - there's product. And now she's standing and delivering. And I think that's one of the reasons [the Billboard performance] was so powerful: not the legal emancipation, but it's a personal growth."

And Ben also revealed the 29-year-old singer was gutted when her performance was initially cancelled by her record label as she felt she has a "responsibility" to so many people.

He added to PEOPLE magazine: "She's aware of her responsibility to other people in this, which I really admire. That's where she was so distraught about when we were getting cancelled. The first thing out of her mouth, after tears, was, 'I have all these people that I'm responsible for.'

"And not just business, but I think she really feels like a little girl grows up, or a little boy grows up, and they see her development and courage and trajectory, and it occurs to you when you're 12 years old, you're like, 'Oh, okay, I can insert my own artistic will in this. I don't have to follow everyone else's path.' We all need that kind of symbol in our lives.

"And it's not easy on the person who is the centre of it. Anyone that would think that this stuff is a walk in the park for anybody should really rethink it. And she's doing it really gracefully, especially what she's been through the last three years. She's really just growing up."