Favorite song to demo or test drive speakers?

Apparently classical listeners never get new systems.
For my last upgrade, the Druzhinin/Muntyan recording of the Shostakovich viola sonata that I ripped myself from a virgin Melodiya lp.  Some of the Bostridge /Ades Winterreise, and a Mahler symphony (maybe 5?).

Why only speakers. Got a new preamp hooked up today. Listening to Art Blakey 'Moanin'.
I could go on.

@mickeyb   The Church and Crimson       Yes sir !          awesome

Gimme Shelter

Important to have several ~~Reference recordings~~~ when determining if a  new piece of equipment is great,,avg or poor,,,and also for revealing mods,, if a  success or a failure,,,Knowing how a  reference cd sounds pre mod post mod, , tube rolling.
Faith Hill, is one such reference,,,opening track You were Right There, ,,, how much passion comes through, Diana Krall. 
Others include,  Sophie Milman, , Gatemouth Brown  Diana Krall