I have an 05 Silverado Z-71 crew cab 5.8 motor

We changed the oil and that same day i noticed an odd whistle noise ... Though i thought it was a simple belt, it then developed into a somewhat quiet but noticeable (Windows up and music off) ...sounds just like a teapot kettle whistle.

It doesn't end there. ... Jumped on the highway the next day ... Whistle still there (have to work lol) and when i get to 60 mph the noise goes to this extremly loud screech of a whitsle (best way to describe is like a bell tone on a PA system that we all cringe at!) If i let of the gas it stops. (attached example from when i drove)

Ive tested it by rpms and it doesn't seem to have a common rpm begin moment. Just high speed 65/70/75 ...any thing below that brings the teapot whistle

Any thoughts??? ive spoken to and taken it to multiple mechanics all of which just want to play trial and error, process of elimination.

Ive tried to recreate the sound sitting still in neutral and park...but nothing ...only when driving.

I've looked for obvious loose hoses and see none... Clearly I'm not a mechanic but any thing that will point me in the possible solution would be EXTREMELY APPRECIATED!!!