The first 20 seconds of "Orgullo" (1974) hit with a powerful sonic punch built on ferocious fuzzed-out guitars, distorted keyboards, and thunderous drums that could easily belong in the discography of Led Zeppelin, The Guess Who, or Cream -- until, suddenly, Las Grecas start to sing and Flamenco rock is born. A few years earlier, in 1969, the brilliant Argentine producer and arranger Adolfo Waitzman had already transformed a harmless light pop tune recorded by a yeyé girl, Encarnita Polo, into a soul-pop hit driven by an irresistible syncopated groove and killer bass lines.