Pablo Beltrán Ruiz (born 5 March 1915 in Los Mochis, Sinaloa, Mexico - died 29 July 2008) was a Mexican composer and band leader most famous for composing the Spanish language song "¿Quién será?", a hit made famous internationally by Dean Martin as "Sway" in 1954, and later by Bobby Rydell in 1960, with English lyrics by Norman Gimbel. Other songs by Beltràn include "Picnic a Go-Go" (1966) and "La Sombra de tu Sonrisa" (1966), an instrumental version of "The Shadow of Your Smile".