Stevan Stojanovic Mokranjac set himself an ambitious task when he sat down to compose a Divine Liturgy for the Serbian Orthodox Church, a setting built on all eight modes, or glasovi, of traditional Serbian chant, one liturgy for each mode. What he actually finished, in 1895, was the setting in the first mode alone, drawn from Serbian chant traditions that themselves trace back to the end of the eighteenth century. The scale of the unrealized plan says something about how seriously Mokranjac took the underlying chant material, this was never meant as a single composition but as a comprehensive musical account of the whole Serbian liturgical chant system, and even the single mode he completed required him to work through the older melodies note by note, stripping away their ornamental and microtonal inflections so a mixed choir could sing them in harmony.
The method he used became his signature. Rather than importing a Russian or Western European choral idiom wholesale, as some contemporaries did, Mokranjac harmonized the Serbian chant's own melodic material directly, leaning on chords built from secondary scale degrees to keep an archaic color in music that was now, for the first time, genuinely polyphonic rather than the single melodic line older chant had always been. The result reads as unmistakably Serbian rather than as a Serbian text set to someone else's choral language, and it is that quality, more than the scale of the abandoned eight mode plan, that scholars point to when explaining why this one completed mode became the standard it did.