Hey for anyone wondering the mall music seems to be "40 Years Young" by Muzak Orchestra
I don't know if they said that anywhere but I just spent an hour searching for it and I think I found it so yeah
The song seems to have a equalizer on it in game, removing and/or quieting down some of the higher tones. It may also be slowed down, due to the pitch difference, though I cannot fully tell.
The closest sounding version of the song I found on youtube was a video called "Muzak Orchestra - 40 Years Young (Mall Open)" by a channel called "Abraham"