Can you measure that and show us the correlation between mood and music?
I´m not sure if moods can be measured. Maybe with a CAT scan?
But cables, amplifiers, DACs, CD players, streamers?
We most certainly can! And compare results. We are able to say which piece of equipment measures better.
Science is also able to say, because we know what the max capabilities of human hearing are, what we are able to hear and if we can hear differences (minus our brains playing tricks on us).
But all that information seems to bother you.
Why is that?
That said, it doesn´t mean that people are not able to make a choice of what is it that they want to buy based on whatever subjective criteria- looks, brand reputation, features, etc.- they might have.
One of the criteria can even be that they think/are convinced that one piece of equipment sounds better than the other, even if the measurements say that is not possible.
But imagine, I´m looking to buy a product.
What is more reliable for me to take in as information as to help me make a decision on what to buy?
1- the subjective opinion of someone (a reviewer for example) or
2- precise measurements
I´ll take the measurements first. And then I´ll try to confirm with my hearing and let all my other senses also participate in the choice.