I’ve already mentioned that songs can begin on any pitch, but the intervallic relationships must not be changed. Let us now explore these intervallic relationships.
We usually use “solfege” (Do Re Mi Fa Sol La Ti Do) to help us learn these intervallic relationships. Instead of solfege, the French often use numbers (1 2 3 4 5 6 7 8). Either system is fine:
You probably noticed there isn’t quite as much space between two steps: MI-FA and TI-DO. This is because MI-FA and TI-DO are “half steps.” All the other steps (for instance, DO-RE) are “whole steps.” It is absolutely essential (and I cannot stress this enough) that you memorize MI-FA and TI-DO as being half steps. In the following video, I start on four different starting pitches, and then (always keeping the intervallic relationships inviolable) go up the first four notes. See if you can hear that MI-FA (the half step) is not as wide an interval as the other steps: