I'm a bit surprised that nobody has yet specifically voiced the argument whether "good" is and objective or a subjective value. Also it seems there has only been a little mention of whether it is an absolute or relative value.
If it is subjective, then for any piece of music SOMEbody may well think it is good, but most likely not EVERYbody will agree. (most of the posts have danced around this idea)
If it is relative, then there must be "not-good" in order for "good" to exist (M.Ted made this point).
To paraphrase P.T. Barnum, "Music can be good for all the people some of the time, and for some of the people all of the time, but music cannot be good for all of the people all of the time"