Answer:
The ascending, descending and horizontal directions of a melody, regarding to its curve, and the starting and arriving notes
A melody or "theme" can have three different directions: it can be ascending, descending or horizontal.
In the first example the melody alternates between ascending and descending motions. But we realize that its generally an upward curve between the first and last notes, so we have a general upward movement. The melody is said "ascending".
in the second case, the melody alternates ascending and descending intervals, but the general trend goes downward, between the first and last note. The motion goes generally downward, and we have a descending melody.
Finally, in the last example, the melody is more static because its first and last notes are the same. It is stable and we get an horizontal melody.
