This Mexican commemorative stamp, issued in 1975, honors the centenary of composer and musical innovator Julián Carrillo (1875–1975), renowned worldwide for developing the microtonal system known as El Sonido 13. The design features a warm sepia portrait of Carrillo in later life, rendered with fine tonal detail and accompanied by clear emerald-green inscriptions. Issued by Correos de México in the 80 centavos denomination, it reflects Mexico’s tribute to one of its most influential 20th-century musical figures. A desirable thematic item for collectors of music, cultural personalities, and Mexican commemoratives.