Well, Einstein, at least, lived quite recently (1879-1955) so music there shouldn't be much of a problem.
Actually, I don't think that Watson is dead, so music should be quite simple there, also.
Oh, and Mrs. Curie was a contemporary of Einstein's, so once you find music for him you're set for her.
So, really, all you'll have trouble with is Newton. He lived in the late 17th/early 16th century, so Baroque would've been in style then.
However, I'll leave it to you to find actual contemporary composers, this is, after all, your project.
