It's well known that she has a strong voice but I assume she learned it from Tony he does it sometimes
Ok it's a little different when an opera star like Anna Netrebtko does it and also ballett dancing and making with the violin player out.
Comparing her with an opera singer? That's a bit a league on it's own isn't it. Happy you choose such an example tho it shows on what great level she is now, amongst her peers that is.