Before addressing the specific topics of the article, let me just ask: was the article complete? All other NATS Journal articles have closed with a list of sources and a copyright statement; this one just cut off seemingly without conclusion. If there is more of it, it would be wonderful to see!
What We Sing
Repertoire is an important choice for both solo singing and choir. The article outlines that choosing pieces for students in choir and solo work must be accomplished with their actual level of development and ability in mind, as well as the consideration of personal vocal Fach. It points out that not only can giving students works that are outside their potential range and preferential Fach be discouraging, it can also be damaging to their developing voices.
Why We Sing
This section of the article deals with the reasons for the required participation of vocalists in ensembles at the university level. It mentions that ensembles do not tend to actually serve the needs of the student, but the other way around, developing a potentially discouraging atmosphere to singers in their development if the ensemble is not meeting their developmental needs as a singer.