Dynamic musical comedy star from the stage who began his career in entertainment appearing in rugged film melodramas (e.g., the unjustly neglected B-film, "King of Alcatraz" 1938) and occasional lighter fare in the late 1930s. His promising early appearances in the Cecil B. DeMille epics "Union Pacific" (1939), "Northwest Mounted Police" (1940) and "Reap the Wild Wind" (1942) did not, however, spell major stardom with the interruption of WWII. When he returned Preston did enjoy good roles in "The Macomber Affair" (1947) and "Tulsa" (1949), but it took a lengthy sojourn on the stage, in which he surprised many with his aptitude for musical comedy, for him to become a major star.

Upon returning to films in the 1960s Preston performed zestfully in the film for which he is best remembered, "The Music Man" (1962), in which he recreated his stage role of an endearing huckster turned unexpectedly successful bandleader. Late in life Preston also garnered praise for two highly amusing performances in the Blake Edwards farces, "SOB" (1981) and "Victor/Victoria" (1982).