I watched this a few days ago. She is a remarkable talent. I didn't know that she was suffering from Parkinsons. That part of the show was really tough to watch.
Excellent movie, watched my CNN recording yesterday. Such a versatile talent.
When she did that Mexican Mariachi song, I couldn't believe what I heard. First she belts out a note held for a few seconds full throttle and then without a pause she continues with an extended downward run (on sung text). That must require some friggin breathing technique. And she does that same kind of thing multiple times in that song.