what is good music?

What you enjoy.

Anything that people want to hear or appreciate. Your first question seems to be the dichotomy of cerebral (brain) versus carnal (soul). To truely be good it needs a blend of both cerebral and carnal appreciation. The examples that show (not prove) this is some 20th century "classical" music that is just a bunch of noise (I'm talking the stuff that is WAAY out there, not merely just atonal, dissonant, or lacking melody). Such music might not offer much carnal pleasures (but maybe not?). Or take some Britney Spears or some "thump, thump, thump" dance music (some rap music actually has merit regardless of what the close-minded says) whose appreciation is mostly carnal and not cerebral (Beethoven it isn't).

I approach it the same way I do with food and cooking. I find the path is both educating and training myself. It's an outward expression of something from within. It's an art. I'll leave this one to the philosphers.

Good music is music that I like. Bad music is music that I dislike. So there.

good music is usually the one that last. A lot of music nowadays you wont hear them anymore after a year or so.

David Bowie good. Fifty Cent bad.
Beethoven good. John Adams bad.
DMBand good. Jimmy Eat World bad.
The Rolling Stones good. Yanni bad.

YES, there is good and bad music. No doubt.