Enz, N. (2013). Teaching Music to the Non-Major: A Review of the Literature. UPDATE: Applications Of Research In Music Education, 32(1), 34-42.
doi:10.1177/8755123313502344
Enz clearly states that he's interested in three research questions.
Because this is a literature review, Enz does not seek to answer these questions himself through applying a specific research methodology. Instead, he is curious to know what answers to these questions already exist so that they can be collected and examined for differences and commonalities. As he states in the concluding remarks, "It is my hope that this article will serve as a catalyst for future discourse and study."
"This paper examines grounded theory within music therapy research." It also does a wonderful job of outlining its methodology, providing a concise overview of results, and a few practical conclusions based on this review of grounded theory literature."
Note the sources used for this literature review (PubMed, CINAHL, PsycINFO, SCOPUS, and ERIC) are quite different from those used in the first literature review example (RILM, Music Index, ERIC, College Music Symposium publications). The only source reviewed by both articles in ERIC.