Please Help

I have a problem , I have downloaded a song at normal speed now I want to speed it up to 2x (double) then I want to post it on youtube and view the song there at 0.5x (half speed) so in effect , the song should play the same as normal speed . But this is not happening , the singer's voice is becoming rough. Look at the difference :
Original Song Justin Bieber - Holy ft. Chance The Rapper - YouTube
My Song Holy Black - YouTube

Please Help . I assume that it is a problem of frame rates .
 
I have a problem , I have downloaded a song at normal speed now I want to speed it up to 2x (double) then I want to post it on youtube and view the song there at 0.5x (half speed) so in effect , the song should play the same as normal speed . But this is not happening , the singer's voice is becoming rough.
Not sure why would you do that and expect loss of definition at every conversion stage.
Doubly so by using cheesy YT algorithms embedded in them.

Similar to halving and then doubling resolution in a picture, you´ll start seeing pixelling and artifacts all over the place, specially on fine detail.
 
In a tape recording you can change the speed and it changes the pitch as well as the speed. It is simply playing teh same thing at different rate.

But modern digital sound works different. When they speed it up, they generally take little chunks out of the sound, so it goes by faster, but the pitch stays the same. And to drop the pitch, they fill in the blanks between bits.