After I comment

We used MP3 because they were small in size, and MP3 players are cheap..
We also didn't know better 20 years ago..
Today I only use wave live...only reduced to MP3 to send via email etc.

Memory is cheap today... we should record wave..

And there is a big difference in audio quality.. clarity , top end, and sizzle suffer in MP3 format..
Experiment .... you will learn the difference..

We are talking about over dub in this post.. This is a major problem ...it doesn't work.. Ask any experienced recording engineer.. he will set you straight