Music for testing equipment speakers, headphones..

There is a very interesting discussion going on at the CA forum about real music suited for tuning or testing speakers and headphones; here is the Link;
http://www.computeraudiophile.com/f8-general-forum/music-testing-audio-equipment-24230/
and a quote from the big introduction article naming a number of recordings best suited for various tasks;

1. Carmen Gomes inc; '' I'm on fire'' from Thousand Shades of Blue
SoundLiaison

Placement is perfect on this young audiophile classic as well as the near perfect natural recording of the voice, but the real test for audio equipment when listening to this recording is it's ability to separate the kickdrum from the upright bass.
The two instruments are playing the same pattern. On less than optimum equipment it might be difficult to separate the two, but with good setup you clearly hear the upright at 10.00 and the kick dead center with a nice decay that one generally do not hear on commercial recordings.
There are lots of speakers and headphones with ''extended lows'' but low with definition is a whole different ballgame.
2 Alban berg Quartet; Bartok String Quartet no.1 in a minor 1th movement. (LP,EMI)
in the beginning of this movement the 4 instruments all play mainly in the same middle and upper register. Despite all that mid and high information the music should not sound harsh.
This recording has the same perfect sound stage as the Carmen Gomes recording.
We believe that this kind of sound stage with such a sense of depth and realistic placement is only attainable when you are recording the musicians in one room at the same time.
[img]http://www.soundliaison.com/images/TSOB200v4-130-10-10-75.png[/img]