Sympathy for Hollenius!
Forget about the acting for a minute, I'm talking about the plot here (and of course this contains SPOILERS).
OK, let's think about what happens in this movie: Christine Radcliffe and Alexander Hollenius are lovers. Without any advance notice, while he's away, she decides to immediately marry her old boy friend, Karel Novak, and announces this to Hollenius on the phone. Novak's nerves are shot; in fact he is such a mental case that he comes close to strangling her the first time he visits her apartment (she still wants to marry him though).
Hollenius is an eccentric, egotistical, temperamental music genius. He's a bit disturbed that Christine, whom he has spent a fortune on in money, time and love, is suddenly leaving him (can you blame him?). But he still gives Karel the chance of a lifetime for his music career. He does this even after Karel demonstrates that he is on very thin mental ice -- able to be totally shaken by a dinner that takes too long before he plays the cello, or by some minor disturbances in a practice session.
Christine is paranoid that Hollenius will reveal the true nature of their relationship and/or do something terrible to Novak. So she murders him in cold blood (totally unnecessarily, it turns out), depriving the world of the greatest living composer. Christine and Karel waltz off at the end with the hope that a good lawyer will get her off easy, as if she deserves this because Hollenius was such a monster.
What's wrong with this picture? Who are supposed to be the good guys here? What kind of morals was this promoting back in 1946? If I wrote the ending, Christine would spend the rest of her life in prison at hard labor with no possibility of parole for this senseless, heartless murder.