Recitative

I discovered what it is that Paco Ibáñez does: recitative: "musical declamation of the kind usual in the narrative and dialogue parts of opera and oratorio, sung in the rhythm of ordinary speech with many words on the same note." 

This is super obvious, I guess, but I hadn't really worked on this section of my book until now. He can write a lot of songs very easily because you don't really need melodies, and this style is well suited to singing the classics of poetry, since the music is in the service of the words.