Tommy Dorsey - Opus One (1991 Remastered) – 1946 " Opus One " (originally titled as "Opus No. 1," but changed to suit the lyric that was added later) was composed by Melvin James " Sy " Oliver (December 17, 1910 – May 28, 1988), an American jazz arranger, trumpeter, composer, singer and bandleader.
In 1939, when band leader Tommy Dorsey decided he wanted a swing band, his first step was to hire Oliver as an arranger away from Jimmie Lunceford 's band for $5,000 more a year. Oliver then became one of the first African Americans with a prominent role in a white band when he joined Tommy Dorsey.
He led the transition of the Dorsey band from Dixieland to modern big band . His joining was instrumental in Dorsey luring several jazz players, including Buddy Rich , to his band. With Dorsey, Oliver continued sharing arranging duties with other arrangers, primarily Axel Stordahl , Oliver doing up-tempo tunes, Stordahl ballads. As James Kaplan put it, "Tommy Dorsey's band got a rocket boost in 1939 when Dorsey stole Lunceford's great arranger Sy Oliver." His arrangement of " On the Sunny Side of the Street " was a big hit for Dorsey in 1946, as were his compositions "Yes, Indeed!" (a gospel -jazz tune that was later recorded by Ray Charles ), " Opus One ," "The Minor Is Muggin'," and "Well, Git It." - more at Wikipedia