Rhode & Schwarz RTB2004 - Scope of the Art - Oscilloscope Music

The RTB2004 is a new bench-top oscilloscope Rhode & Schwarz ... been out maybe 6 weeks or so (ordered mine on launch day, but yeah, just arrived). Just wanted to do something fun with it to start out... yeah I know my "camera" work could be better...

What author intended it to look like:
   • Jerobeam Fenderson - Planets  

Track 6 of the audiovisual album Oscilloscope Music
available at http://oscilloscopemusic.com
Just a few bucks to support his work.

What I can't figure out at this point is why even though I am on DC coupling, and the traces look right on, still seems that the X-Y is doing a little ac coupling like centering even using the proper files.

Oh well.... this was done with an external sound card thing...