I think a baby's intelligence level depends on their genes, how they were born, and on their brain themselves. If they were born with an underdeveloped brain, they won't be as bright as everyone else. To make a baby smarter, teach them vocabulary, let them excercise their brain by doing math problems, ELA questions, etc. :)
A baby's potential will not be affected by music, or TV shows, or stuff like that. What they need is stimulation. Mental exercise. So instead of just listening to Mozart, you should do puzzles, take your baby to experience new things, keep them active and interested. And most of all, don't park a baby in front of a TV. Those brightly colored shows are unnecessary and don't really do anything for babies... in fact, they can be harmful.
The American Association of Pediatrics says not to expose children under 2 to TV. Even children over 2, they will always learn better from human interaction than from media.
YOU ARE KIDDING RIGHT? you really think it's that stupidly simple? When the kid comes out just spend a lot of time and energy exposing her to new challenges and convey a joyful expectation that the child will solve them.
Music doesnt really make a person smarter, it simply enervates certain areas of the brain so learning can be easier. It may expand the brains capacity by forming or helping form new gyri and sulci as well. As simeone said, if a child is genetically low IQ music isnt going to make that much difference. Mozart and a lot of other classicle music helps.