I know the difference between the previous two sentences is that 'the music' is specifically talking about a music.
Is there any more difference in meaning? Can you tell me some cases where the definite article isn't required?
I think you got it just fine:
You use the article when refering to some specific instance of something,
without article, you are making a general statement, often about the type of something.
Some examples:
"I like fish" (...but don't like pork) vs. "I like the fish" (...which is on my plate.)
"I dread christmas" (...because it's always such a hassle) vs. "I dread this christmas" (...because my Mum died last month.)
"I see clouds" (here, whereas you, somewhere else, see sunshine.) vs. "I see the clouds" (...threatening to rain on my laundry and yours.)
