Glenn Miller's reign as the most popular bandleader in the U.S. came relatively late in his career and was relatively brief, lasting only about three and a half years, from the spring of 1939 to the fall of 1942. But during that period he utterly dominated popular music, and over time he has proven the most enduring figure of the swing era, with reissues of his recordings achieving gold record status 40 years after his death.