Sentence:  His album... dealt with the song form of Puerto Rican back-country troubadours, and it had a preoccupation with... the <WSD>décima</WSD>, a 10-line stanza with specific rhyme schemes. 
Meaning of the word marked with <WSD> tags:  A 10-line verse or stanza,  in the form of a song comprising an introductory verse followed by four such divisions.