He attended Madrid University, first studying history but then switching to music. He was co-director of the Revista Musical Hispano-Americana (1914-1918) with Rogelio Villar. He studied composition with Bartolomé Pérez Casas, and is said to have studied with Maurice Ravel, though little documentary evidence exists. In 1915, along with Manuel de Falla and M. Salvador y Carreras, he founded the Sociedad Nacional de Música, serving as secretary until 1922. In the late 1920s, he turned his attention from composing to devote himself to music criticism. In his columns for El Sol between 1918 and 1936, he both reviews concerts and discusses trends in the Spanish public's reception of classical music. His activities as critic and historian intermingle, though the second became more important over the years and is a consequence of the first. Salazar corresponded with many of the leading intellectuals and composers of his time, including José Ortega y Gasset, as well as members of the Grupo de los Ocho including Jesús Bay y Gay, Ernesto and Rodolfo Halffter, and Salvador Barcarisse. In 1932, he attended the International Congress of Arab Music in Egypt. In 1937, Salazar went to Paris to carry out a propaganda mission on behalf of the Republican government. In 1938, he was named cultural attaché for the Spanish Embassy in Washington, D.C. While in the United States, he organized courses in folklore at the University of Middlebury in the company of Joaquín Nin-Culmell. In 1939, he moved to Mexico at the invitation of Mexican president Lázaro Cárdenas del Río, and continued to write essays and monographs on European music. From 1939, he taught at the Colegio de México, and from 1946 at the Mexico National Conservatory. In 1947, he gave a lecture series at Harvard University titled "Music in Cervantes," and two years later was awarded a Guggenheim fellowship. He died in Mexico City in 1958. Salazar's earliest works ("Estampes," "Jaculatoria") have Spanish-style nationalism. His style evolved in the mid-1910s toward Impressionistic techniques: parallel chords, lack of clear cadences, and avoidance of major or minor modes. His most successful works are the two for string quartet, "Rubaiyat" and "Arabia".