I've heard it has an effect on the fetus. There are varying reports, and research, on the prenatal concert hall. We do know how important it is for the mother, and the father, to sing, chant, read poetry, and stories, to the unborn child. I am certain listening to music at a moderate volume for 15 minutes at a time, once or twice a day, would be ample. I suggest for the mother to give equal time to listening themselves, and their child listening.
Music can be an oasis to bring the family and community together.
Newborns do not hear sounds like we do. Their ears are still filled with liquid. Young babies need quiet time, as well as stimulation. Make up melodies for changing time, for eating time, and perhaps, the family meals should be a time where TV and radio are turned off, and simply a little Mozart in the background brings the community of the family to harmony. I understand that studying music has a positive effect on a child's math abilities.