what is the difference between good and bad music

To borrow from a famous dog trainer: "There is no bad music only bad listeners."

Rap may be good, but is it music?

I am with PCS about being like Albertporter when I grow up. Awesome collection of artists that makes me want to check out the ones in your list that I am not familiar with.

the changeability of personal taste is fascinating: how many times have we pulled out a piece of music we used to love/not love, only to find that our feeling about it has flipped 180 degrees? it makes selling 'unwanted' CDs/LPs a risky proposition indeed...

another interesting note on this subject: some musical instruments (stringed especially) are just naturally louder and have better timbre when they are tuned properly. now how do you explain that? are there preexisting C#s in the universe?

albert: if you are open to Stockhausen, you might try to get your hands on Kim Cascone's 'Blue Cube' or 'Cathode Flower' - very cool computer-generated music by an associate of Angelo Badalamenti (Twin Peaks) or Jon Wall's 'Fractuur' or 'Alterstill' - music constructed of samples of 20th century composers (which doesn't sound sampled at all; it sounds composed and seamless)

Any Psychiatrist would say that what we percieve should be percieved by the vast majority of others for it to be true. This is called the reality check.
Therefore by definition Pop music is good and everything on the fringe of lunacy in terms of preference. I think that the current generation of popular music is mostly unlistenable so I am clearly unable to discern good music from bad, I listen to what makes me happy, even classical which no one listens to anymore (except a few of philes).