Pink Floyd
The Dark Side Of The Moon

When you talk or discuss music with someone... before delving into the topic it is advisable to ask the following question?

"Sorry... but do you have The Dark Side of The Moon?"

"No"*

"Then what are we talking about?"

*Note from the time-wasting editor:

for completeness, one should also provide the subsequent thesis in case of an affirmative response from the interlocutor;