True enough traditional storytelling relates to song often enough. But even where it doesn't it'd still belong above the line.

Pedantic point - oratory isn't some higher level of rhetoric. The historical distinction between oratory and rhetoric is that oratory is one component of rhetoric, the art of actual delivering a speech, the other aspect being putting the words together, either in advance or on the hoof.

The crucial element in oratory is that the speaker succeeds in moving or convincing the people who are being addressed (who some cases may not be the people who are physically present - as for example in such as case as Nelson Mandela' famous speech from the dock). It's not a matter of meeting some set of rules about oratory, it's a matter of does it work.

In the singing context it'be a matter of, "Does the performer get the crowd singing their hearts out?" - and that's a different question from is it a great song, is he or she a great singer, or even is he or she sincere. Those are important questions but they don't stand or fall together.

It seems pretty self evident that Obama does indeed, metaphorically and even literally at time, get the crowd singing their heart out.