Hidden urges
It is not possible (i.e., it should not be possible) to sing two tones in a row without feeling a pull between them: this one wants to go up; that one wants to stay in the same place. This is what produces what in jazz are called “blue notes.” You don’t have to be Ella Fitzgerald to get it. Just let yourself go. Forget about right and wrong and feel the hidden urges. The tones tell you what to do.