More information needed. It would be helpful to identify which tracks, but the current beta does not show you the track info yet.
Do you have some software setting enabled to boost volume past 100%, or anything like that? It sounds like you're describing clipping; the music is at close to 100% volume by default, so if anything boosts it past that, you may encounter clipping. In a future version we'll add volume controls in the menu so you can try adjusting those as well, meanwhile try adjusting your software volume down?
It's only on a few of the new songs, everything else is normal.