I'm not sure why Villa-Lobos's Harp Concerto isn't better known. I realize it will always be ranked well behind Ginastera's great concerto, especially in the great Argentine's Centennial year. And Villa's Harp Concerto isn't at the level of the Guitar Concerto, or the 2nd Cello Concerto. But it deserves a listen.
Here is Villa-Lobos between two great musicians for whom he wrote the Guitar and Harp Concertos, Andres Segovia and Nicanor Zabaleta.