Nikos Skalkottas’s Concerto for Violin, Piano, and Orchestra (Berlin 1930) was the first among fourteen concerto or concerto-like works he composed during his lifetime. In terms of form, this concerto has many differences from the following ones. On the contrary, in terms of thematic and motivic development, as well as harmonic language, it exemplifies the use of fundamental compositional techniques that were to become idiomatic for his compositional style thereafter. One of them is the use of diatonic elements that either originate from Greek folk music or stem from the inner workings of the music’s harmonic organization. This article attempts to explore these diatonic elements and the ways in which they function in this concerto. It demonstrates how these elements may be organized into five categories and then proceeds to analyze particular passages of the work by focusing on issues of centricity and functionality. Considering the analytical requirements regarding the work’s harmonic material, the analyses are methodologically based on Forte’s theory of pitch-class set genera, which provides a systematic frame of reference for the characterization of harmonic species in 20th-century musical compositions.