Invert ?

Years ago I had a preamp with a phase inverter button on the remote.  It didn't take but a few pushes now and then to realize I couldn't hear any difference one way or the other.  

I believe I read somewhere that there is a listing of songs, albums, whatever, that lists those that were recorded ending up with the phase inverted.

I also believe that I read somewhere that even different songs on a single CD, LP, can end up with some correct and others with inverted phase.

To get a baseline of what phase inversion sounds like, push the invert switch on your preamp for any song you are currently playing and listen if you hear a difference.  If you do, you will know what to listen for in inverted tracks.