The violinist argument is an implausible hypothetical situation presented in order to argue in favor of abortion. The argument imagines that you woke up attached by medical tubes to a sick, unconscious, but very talented violinist who needed the support of one of your organs in order to survive for the next nine months. After that nine month period -- the same amount of time required for gestation by a pregnant woman -- you would be detached and the violinist would walk away healthy again. Do you have a right to detach the tubes now, resulting in the death of the violinist? Someone who supports abortion is likely to answer "yes", and if that is the correct moral answer then why should abortion be any different?
There are many compelling responses to this argument. An accomplished violinist is not a helpless unborn child, and there is no special obligation by a stranger to a violinist as there is by a mother to a child. Moreover, while a pregnancy can be difficult for particularly older women, a pregnancy for most women who consider abortion is not nearly as burdensome as being bedridden with tubes connected to a stranger for nine months. In addition, the hypothetical situation is not one that occurs about a million times a year in the United States, as abortion does.