If you are part of the cool music crowd, these are the rules:
Never like a song that made it to the top 40. It's only cool to like the more esoteric songs from the same album.
You MUST like Led Zeppelin
Bon Scott was way better than Brian Johnson, despite Back in Black being the 2nd best selling album of all time. Therefore, you can own Back in Black but you must always comment that Highway to Hell was far superior.
You are not allowed to enjoy love songs
The Who is a good band
If you pick a favorite Beatles Album, it must be The White Album or another one of their later releases.
Never go into a record store and buy what appeals to you. You must stock your shelves with the right CDs in case you have guests who happen to look through them.