In case you haven’t read it, Rand rejects the usual definitions that you list and drills down to the fundamental distinction between drama and melodrama, based on her idea that there are only two kinds of fundamental conflicts in fiction: internal (value vs. value) conflicts–drama, and external (man vs. man) conflicts–melodrama. Its important to remember that these are logically fundamental types—because you can pick up any book on fiction writing and it will list a dozen different kinds of conflicts: man vs. nature, man vs. the supernatural, man vs. aliens, man vs. society, etc. But Rand, I believe, would maintain that these are perhaps useful but lesser categories of conflict that fall under the fundamental categories of human conflict action: internal and external.

“A drama involves primarily a conflict of values within a man (as expressed in action); a melodrama involves only conflicts of a man with other men.).”

She gives a simple example that illustrates the difference: If the exciting action of a melodrama consists of a detective pursuing an unknown criminal, and then the detective discovers that the criminal is his own son, the melodrama is lifted to drama–because now the detective is caught in a crusial internal conflict between his love for his son and his duty as a policeman.