Billy May has said that he became an arranger because he had so much time to observe the other instruments when he played tuba in high school. He worked with a variety of Pittsburgh bands until he introduced himself to Charlie Barnet, who was touring through town, and offered to write an arrangement for Barnet's band. He ended up becoming one of Barnet's main arrangers and was enlisted as a trumpeter when Barnet reformed his band in 1939.

May took an Indian-inspired tune that Ray Noble had played on a suite of such pieces and arranged it for Barnet. The result, "Cherokee," was Barnet's biggest hit, one of the biggest of the swing era, and a key inspiration for bebop (Charlie Parker's "Ko-ko" is based on the changes in "Cherokee"). May ended up rewriting the entire Barnet book from scratch after the original music burned in the Palomar Theatre fire in October 1939. The next year, Glenn Miller hired him as an arranger and trumpet player. When Miller broke up his band before reforming it as the Glenn Miller Army Orchestra, May quit and moved to Los Angeles. Source: Space Age Pop