I recently discovered my whistle register. I think I am doing it right, but I need to make sure I am. I don't want to do any damage to my vocal chords, as I am a good singer, and have always been told so. I consider myself good too. I can hit an f6 pretty effortlessly, but sometimes it's difficult to go higher. Sometimes I just can exhale and it comes out great, but other times it seems like I need to almost squeeze a bit to get higher? They also sometimes sound really shaky, like in the second video below. My whistles also sound squeaky. I am a young female singer, btw. My problem is I am not sure if I'm doing it right, and when I descend slowly down to a high c, my voice cracks and I end up singing an e5. really weird, I know. I am trying to connect my head voice with my whistle voice because they are disconnected and I am worried I am doing it wrong. Sometimes, it's also hard to do whistle tones, but usually I can get them easily. However, when I try to sing along to a song with a whistle section in it (the way, ariana grande) I can't do it well. I can do random pitches, but in order to do a melody, I can't because it connects head voice and whistle tone, for example: in the song, it starts with a b5 then a c6 and goes up to f6, but I'm not connected in my head voice and whistle. How can I connect them? also, my whistle tones are squeaky. Any help? :/
Here is my video on a simple f6 down to d6 whistle tone: https://youtube.com/watch?v=X8Q5kLpP1Uk
Now here is what keeps happening, the cracking at c6: https://youtube.com/watch?v=p4f9DvBG0yQ