So how do I put together these two things:
a] Lorca is the modern poet (and the Spanish) most often set to music.
b] Lorca was a poet/musician who formed part, or was associated with, a musical "generation" that renovated and modernized Spanish music.
First I thought of these as essentially separate things. As researched deepened, I saw b more as more as the cause of a.
Now I want to look at how many composers of Lorca's own group set his work to music. That is a missing link. At first, I didn't know of much, but more is emerging into view, for example, María Teresa Prieto, a Spanish composer who wrote all her music in Mexico. She is never mentioned as part of the "Generation of 27," but she was part of it later by one degree of separation.
The thing that comes to play here: Spanish music is not known. Falla overshadows everyone else. Even people who work on Falla hardly mention his disciples. Orringer, in his book on Lorca and Falla, doesn't bother to mention the musicians of Lorca's own generation. I hardly know them myself. Scores and recorded performances are hard to find.
A second factor, related to this. The civil war and exile had a disastrous effect on these composers.