Same song. Same second. Two versions.
Press play, then switch. Both versions run at the same level, so you hear the mix instead of the loudness.
Demo pair
Loading both versions.
The rough has the bass swamping everything, the drums flat, and the top end dull. The mix pulls the low end back, opens the top, and puts the lead where the ear expects it.
What to listen for
Start on Verity, then hit Rough. The first thing most people notice is that the low end stops swallowing everything.
Then listen for the lead. In the rough it sits behind the music. In the mix it sits in front of it without being louder.
Why match the levels?
Because louder always sounds better for about four seconds. Matching removes that so you hear the actual decisions.
Is this the same take?
Yes. Same performance, same second, same section. The only difference is the mixing.
Can I hear my own song like this?
Send it. You get a short rough treatment back so you can run the same comparison on your record.
Why do they loop?
Short sections repeat so you can switch between them a dozen times without restarting.