I am reading this paper: Toward a Musical Analysis of World Music
On page 4 there is this statement:
All of the songs are syllabic and are subject to clear harmony (prototype degrees [I, V, IV] and “strong” progressions [Schoenberg 1954]): Song 1 has one chord (as a tonic [I]); song 3, I–V– I ; song 5, I–IV–V–I .
And on page 6 there is a picture visualising the statement.
So, my questions is: How one can see that "blocks" of notes, shown in pink rectangles belong to a claimed chord?
For example, in the song 3, the second block consists of "re" and "fa" notes, why is that chord V? Should chord 5 consist of "sol" "si" and "re" notes?