Every audiophile has a trusted selection of recordings that helps them evaluate the sound of a set up. Even though it is often apparent almost within the first few seconds of listening to a new piece of kit, or a modification to an existing one, whether the sound is preferred to some reference, in order to break open the sound and establish the differences between them it is necessary to listen to some specific music. For me it has to be pieces I know well – music that I can remember and that has some distinguishing features to listen out for.
It is rare that I hear something new in these recordings now but the definition of what I am listening for most certainly varies from one audition to the next. I generally listen for the highs, the lows, and for detail first before judging the more emotional attributes like dynamics, timing and involvement.

Up High.......

The high frequency performance betrays itself primarily in the level of distortion and the tendency of the sound to produce fatigue in the listener.
In experimenting with amplifier configurations and passive components I have found that whilst I sometimes cannot definitively attribute a change in the sound.
I have found that on occasions it jars in someway and that I am less prone to listen for long periods of time nor feel the desire to try another record almost before the one that is spinning has finished.
In my experience if there is a problem in this respect then almost any music will show it up. Such a phenomenon has frequently been ascribed to high order odd harmonic distortion. I use two very different songs to test for high frequency performance "Porcelain" by Moby on his Play album and "Pie Jusu" on Andrew Loyd Weber's Requium.
The Moby track vocals can sound too metallic and harsh in some set-ups I have tried. This track I find usefull for setting tracking and stylus alignment because of its susceptibility to this problem. Incidently, "Porcelain" in followed by "Why does my heart feel so bad" and the keyboard playing on this track will betray any hint of wow or flutter. I know because the first copy of this LP that I bought had a hole that was slightly off centre - enough to make the record unplayable such was the obviousness of the pitch oscillation.
On the other record, the vocals of Soprano Brightman and Treble Miles-Kinston singing Pie Jesu should be easily differentiated on a well tuned system. Do Brightman's eses sound sweet or zizzy? In fact this album is rather good as a general test of nearly all the musical attributes required to characterise a system.
The music may not be to everyone's taste but it is well recorded and performed by accomplished musicians.

Deep Down......

For bass response I listen to Simply Red's "Sad Old Red". The bass line runs quickly show if there is any resonance in the lower regions that make some frequencies louder than others. This is particularly important when judging loudspeakers. Of course much is made of how deep a loudspeaker will go – can it reproduce those gut wrenching sonics in the low tens of Hertz so prevalent in modern music? I use Leftfield's "Rhythm and Stealth" or Madonna's "Ray of Light" albums for this test.
Nearly all the tracks go down really low and when played loud just watch those woofers. If they are long through drivers they will be tested to their extremes with this material. Try Leftfield's "el cid" and listen how low the underlying synth goes as it slides down the frequencies.

What's actually recorded?.....

Listen for detail in recording I find one of the most frustrating aspects of testing - is it really there or am I "rembering" what should be there from experience. Madonna's "Till death do us part" as suggested by Geoff Husband is a good test track: Is there articluation of "He" when she first declares "He's not in love with her anymore"? Sometimes I think I can hear it on others I am not so sure. The Wall by Pink Floyd is another favourite of mine. There are numerous background sound effects on this work. For example between "Another Brick in the Wall" and "Mother" it should be easy to discern the three spoken phrases that are separately repeated but faded back as the first track ends and the other starts. How many times is "any pudding" recorded – five, six? Another good test is Chris Rea's "The Road to Hell". At the start of this track there as a number of radio traffic bulletins. One of them repeats over and over again "KPW more bad news for folks on the freeway".
It is easy to hear the "more bad news" phrase throughout but freeway can be a little masked by what else is going on in the mix. Most tricky of all is to make out the P in KPW. The last couple of repeats before enter the next phase of the song provide the clearest opportunity to hear the P.

Foot Tapping Stuff.......

Timing is an elusive but essential quality. All records sound "better" in a system that times but for sum it is essential. To test for timing one track I use is by Tin Machine on their eponymous album called "Heavens in Here". This track only really boogies if the instruments are in the right place with respect to each other temporally, especially in the last third of the song.
I have often heard criticisms levelled at this David Bowie era but for me Tin Machine produced some great stuff and I wonder whether some of its critics have actually heard it on a system that can time properly.

Fireworks........

For imaging and dynamics I use "Dance of the Flames" by Incantation. The pan pipes and assorted instruments on this track are very well separated in the listening plane and the composition really jumps around to provide that evocation of flames in a fire.
Another good record to test for stereo pyrotechnics is "Women in Chains" by Tears for Fears. Also the vocals are quite complex and revealing of the systems general articulation.

Being There.......

For emotion and communication I normally prefer live recordings and as a rock fan I often turn to Thin Lizzy's "Still in Love with You" on their Live and Dangerous double album. This track has a great bass line and expressive vocals as well as some well-crafted guitar.
Another recording for guitar fans can be found on the Wishbone Ash live recording of "Persephone" on their Live Dates Volume 2 Limited Edition with the extra disc.
With both of these live records the sense of being there is tangible with all the instrumental contributions being independently discernible. My latest favorite, however, is SongBird by Eva Cassidy - superb performer, well recorded and pressed onto virgin vinyl that is almost silent.