The rubric of this first fantasia for 4-course guitar declares that it “has to be fretted like a vihuela with ten frets [and] has to have a ‘bordón’ on the course.” That is, the fourth course needs to be strung at the low octave, not up an octave. Mudarra indicates a slow tempo and the first mode.

It is quite a short attractive piece, in what is the earliest Spanish guitar source. The fantasia begins with quasi imitative sections, then becomes increasingly free and instrumentally dominated. It is a good example of homogeneity in diversity and of clearly directed growth through controling the density of redobles, blossoming into homophony at c. 56ff, and then slowly working down to the final cadence. Shows development of certain structural ideas eg. Phrase 1 = 2+2+3 measures, 2nd phrase omits middle two measures to be 2+3. There is some internal repetition of material: c. 37-8 = 54-55, and c. 26-30 = 47-51, but glossed in the repeat.

The following diagram indicates the way the work is structured.