Consider the following premises. For all z, z will drink water or z is not a doctor. For all z, z is a doctor. There is at least one z for which z is a musician. Can we infer the following from them? For all z, either z will drink water or z is a musician are not true.
 From the fact that for all z, z will drink water or z is not a doctor we can infer that for all z, if z were a doctor, then z is drinking water. From the fact that for all z, if z were a doctor, then z is drinking water, and that for all z, z is a doctor we can infer that for all z, z will drink water. Finally, from the fact that for all z, z will drink water, and that there is at least one z for which z is a musician we can infer that there is at least one z for which z will drink water and z is a musician, which contradicts that For all z, either z will drink water or z is a musician are not true. Therefore, the answer is no.