Christina Aguilera, singing very sick

There's something that impresses me in professional singers with big voices: their endurances. Here is a video of Christina Aguilera singing with Chris Mann in the final of The Voice season 2, where she was her vocal coach. 
She was sick like a dying dog, she couldn't even speak that night. However when it was her turn to sing with her pupil on the show she was awesome as always, no one would have ever imagined she was almost voiceless that night.
To see this unforgettable performance click the Here.
Enjoy!

Pink, one of the best voices of all times

Pink never disappoints me, what a rich way to perform every single one of her songs. From the point of view of a vocal coach you can tell how dedicated she may have been when growing when training to develop her talent.
Here's Pink delivering a killer performance at the Grammys in 2012, her voice is impeccable, her timing and stage presence are a delight to watch.
I hope you enjoy this vocal performance as much as I did.