I feel this too, what I do on my multimonitor setup when I'm listening to podcasts or music is go to shadertoy.com, find a shader that isn't too flashy, and fullscreen it for hours. You might have to edit some values and recompile the shader (press the play button on bottom-left of the section of code), but you can get some great results that way.
My go-to these days is Neon Parallax with the 1.2 and 0.8 values under //global movement replaced with 0.2