Harry Haag James was an American musician who is best known as a trumpet-playing band leader who led a big band to great commercial success from 1939 to 1946. He broke up his band for a short period in 1947, but shortly after he reorganized and was active again with his band from then until his death in 1983. He was especially known among musicians for his technical proficiency as well as his tone, and was influential on new trumpet players from the late 1930s into the 1940s. He was also an actor in a number of films that usually featured his band.

A big band or jazz orchestra is a type of musical ensemble of jazz music that usually consists of ten or more musicians with four sections: saxophones, trumpets, trombones, and a rhythm section. Big bands originated during the early 1910s and dominated jazz in the early 1940s when swing was most popular. The term "big band" is also used to describe a genre of music, although this was not the only style of music played by big bands.