Lilt
The direction of melody is simply called it's motion.
There is no saint named Melodie.
The term for a second melody that accompanies the main melody in a musical composition is called a "counterpoint."
The main tune is called the "head." It establishes the chord structure and overall theme.
It is not. You can change the different sounds it makes, but you can't alter the pitches to make a melody. However, maybe if you got a bunch of them, you might find ones with different pitches and can make a melody out of that!! =) If you're looking for that light, high-pitched sound to make a melody with, an instrument called a Bell Kit or a Glockenspiel would be for you! Hope this helps!!
melody
a melody
phrase
Phrase
there are different words: mix overlap mash up melody 1 & 2
The "A" melody
In opera an aria