Mercury Records is a record label operating as a standalone company in the UK and as part of the The Island Def Jam Music Group in the US; both are subsidiaries of Universal Music Group. There is also a Mercury Records in Australia, which is a local artist and repertoire division of Universal Music Australia. In the United States, Universal Music Group Nashville administers the Mercury Records Nashville label.

Mercury Record Corporation was founded in the American city of Chicago in 1945 by Irving Green, Berle Adams and Arthur Talmadge. They were a major force in jazz and blues, classical music, rock and roll, and country music recordings. Early in the label's history, Mercury opened two pressing plants, one in Chicago and the other in St. Louis, Missouri. With the use of automatic presses and providing 24-hour turnaround, they went into direct competition with major recording labels such as Columbia, Decca, and RCA Victor.

By hiring two promoters, Tiny Hill and Jimmy Hilliard, they penetrated the pop market with names such as Frankie Laine, Vic Damone, Tony Fontane and Patti Page.

William "Count" Basie (August 21, 1904 – April 26, 1984) was an American jazz pianist, organist, bandleader, and composer. His mother first taught him piano and he started performing in his teens. Dropping out of school, he learned to operate lights for vaudeville and improvised to accompany silent films at a local theater in his town of Red Bank, New Jersey. By 16, he increasingly played jazz piano at parties, resorts and other venues. In 1924, he went to Harlem, where his performing career expanded; he toured with groups to the major jazz cities of Chicago, St. Louis and Kansas City. In 1929 he joined Bennie Moten's band in Kansas City, and played with them for years, until Moten's death in 1935.

That year Basie formed his own jazz orchestra, and in 1936 took them to Chicago for a long engagement and their first recording. He led the group for almost 50 years, creating innovations like the use of two "split" tenor saxophones, emphasizing the rhythm section, riffing with a big band, using arrangers to broaden their sound, and others. Many notable musicians came to prominence under his direction, including the tenor saxophonists Lester Young and Herschel Evans, the guitarist Freddie Green, trumpeters Buck Clayton and Harry "Sweets" Edison and singers Jimmy Rushing and Joe Williams. Basie's theme songs were "One O'Clock Jump," developed in 1935 in the early days of his band, and "April In Paris".