Pablo Beltrán Ruiz (1915–2008) was a celebrated Mexican composer, arranger, and bandleader whose elegant blend of Latin rhythms and big band sophistication earned him international acclaim. Best known for his timeless hit “¿Quién será?”—popularized globally as “Sway”—Beltrán Ruiz became a defining figure in mid-20th-century Latin music. His work seamlessly fused mambo, cha-cha, and bolero traditions, captivating audiences with its grace and rhythmic vitality. Through his orchestra and compositions, he helped bring the vibrant sound of Mexico’s golden musical era to listeners worldwide.