This is a 30 second sample of Dream Theater track "These Walls" from the album Octavarium. The sample range is 2:34 - 3:04. I use this sample to test encoder stereo imaging transparency.
Here is a quick ABX that I just did in Foobar of lossless source versus Ogg Vorbis @ 128kbps.
(http://img.photobucket.com/albums/v290/korben_dallas/foo_abx_dt_tw.jpg)