I find it curious that folks here often refer to seeing live music as a reference point for what a speaker should sound like. It seems to me that the vast number of live listening experiences will be subject to similar potential for alteration/colouration as a stereo system. Even acoustic sets are usually played with mics, amps and speakers, sometimes in a place with good acoustics, sometimes bad. It seems that our references for natural sound might be limited to the sound of a voice or an acoustic instrument without a mic (which is certainlly do-able)
So if I want to see if a speaker sounds natural I should choose CDs, LPs which represent these sounds and instruments (ie. piano, voice, acoustic guitar, strings, horns or other instruments which I have recently heard live and un-amplified.)?
When it comes to rock etc it seems that it pretty much comes down to my taste in what sort of colouration or sound I like those tunes to have. It's just taste. And hence why we all like different speakers and there's so much to choose from.

I am recently auditioning speakers (and learning) so hence my preoccupation.

Any thoughts?