Can the level of pleasure derived from music be measured?

Not  much for measurements can look good but still sound bad 

look at tube amps they are no where near as clean in measurements but we all know tubes have their own Sonic goodness.

It's Schroedinger's cat hissing at us...

The fact that we are performing measurements affects the subject, and places the subject under stress. The added attention and stress to perform will change the emotional state, greatly skew the results. So, while we will get readings, they will refer to how a person feels under duress, and will provide data that is more useful about the stress tolerance levels of the subject.

We would get inconclusive data, as the state we want to relate is is the state where there is no duress, no stress affecting the "results".

No. #1 you'd need an MRI and #2 there would be no way to distinguish between pleasure derived from the tune vs. the sonic quality of said tune.

"a true audiophile hierarchy can not be claimed"  sure it can. I'm 13th.

I think you would need Woody Allen's Orgasmitron from Sleeper to accurately measure pleasure.

@frogman just love you post! And to the OP, I do under stand the idea of hierarchy which may have many definitions depending on who you ask. I postulate that as a surrogate or proxy to your direct question and I believe to be true for myself, there might be a relationship between the pleasure derived from the listening and and the amount of time spent researching articles, understanding electrical engineering theory, studying schematics, making informed decisions about purchasing gear, building sound spaces etc. and the pleasure one derives form the mind quieting combination of rhythm and melody from perfect phase and time correct audio signals reaching the ear. OP are you a neurologist? I ask because heard an npr story re neurological studies about brain activity when rhythm and melody are heard together. Peace