This is not specifically aimed at my Axioms, as I have several sets of speakers in several vastly different quality systems, but these are musically choices I like to audition any piece of audio equipment with:

Steely Dan - Hey Nineteen (actually most tracks on the Gaucho Masterphile LP)
Simply Red - Sad Old Red (Picture Book LP)
Barbra Streisand - The Broadway Album (almost the entire CD is exceptional on good equipment)
Duke Ellington Orchestra - Digital Duke (a GRP Allstar cast of modern Jazz legends - CD or LP)
John Hiatt - Memphis in The Meantime (Bring the Family CD - extremely complicated bass/drums)
Tears for Fears - Famous Last Words ( Sowing the Seeds CD - my ultimate track to determine quality)

I also like to challenge them on different styles of music - Heavy Metal, Rock, Jazz, Classical. The tunes should have quick action, with lesser points intermixed.

These prove a dificult task for some speakers, while others shine.