I did write the list myself. I got the information from forums and friend and downloaded the songs myself to personally varify the notes. I also am adding people who hit either D6 or Eb6 effortlessly to hint that they can perhaps touch the whistle register like Ashanti who only hits Eb6, as well as Kandi Burrus, Patti Labelle and Emmy Rossum, and Krystal Harris who hits D6, and a couple others. But there are alot of singers who have sung in the whistle register a frequently like Betty Wright is known as the starter of the whistle register which she hits in Babysitter, No Pain, No Gain, and After The Pain. Amel Larrieux hits F#6 in For Real and in the first track of her new album she hits like E6 or something I didn't check it though. Shanice and Debelah Morgan also do it frequently and are compared to Mariah in their skill at it. Such as Shanice's overall voice and Debelah's enunciation in it. I'm pretty much all the information you'd need if you ever want to know such information on a singer. And I made the list cause I don't trust people. Like people always get notes wrong. Like Blu Cantrell's B6 is really Bb6. And Whitney Houston has actually hit G6 but some say its A6. She seemed to have done it by accident though. It was during a live performance of I Wanna Dance With Somebody. It's on youtube I think but for me it doesnt load all the way and appears to.