One of the keys to successfully setting up a stereo system is variety and variability. Make sure you use a broad variety of music that covers the gamut of tones and imaging challenges even if you don't wind up ever listening to it again.
For example, if you're in the process of setting up your speakers for best tonal balance and imaging, so you can eventually enjoy your classical music tastes, making sure a smattering of well recorded rock, jazz, and classical will offer better results than just focusing on your core listening tastes.
A Mahler symphony, Miles Davis, and Billie Eilish should all sound correct on a well-setup system.
Variety helps smooth out the dips and bumps and leads to a better sounding stereo system.
