El Reloj is a progressive rock band that emerged out of the Buenos Aires rock scene of the 1970s. The band consisted of Willy Gardi (lead guitar), Juan Esposito (drums-vocals), Eduardo Frezza (bass, lead vocals), Osvaldo Zavala (guitar) and Luis Valenti (Hammond Organ, vocals). Their brand of music usually garners comparisons to Deep Purple. By employing blues rock riffing, complex song structures, symphonic tendencies and breaks in their music, El Reloj acheived much fame within the Argentine capital's underground rock scene.