It is never morally permissible for a woman to have an abortion. Even if we accept that the fetus is a person with a right to life from the moment of conception, it doesn't follow that it is never morally permissible for a woman to have an abortion. The fetus is a person.
Every person has a right to life.
The mother has a right to bodily autonomy, that is, the right to decide what happens in and to her body. The right to life is stronger and more stringent than the right to bodily autonomy and so outweighs it in cases of conflict. Therefore, it is wrong to kill the fetus. The famous violinist is a person. Every person has a right to life.