What was duke ellington's band name?

The Duke Ellington Orchestra, or sometimes Duke Ellington and His Orchestra.

Duke's band

Didn't have an official name, but was generally referred to as Duke Ellington's orchestra (note, little O vs. big O), and also the Ellington orchestra.

Ellington formed his first band, The Duke's Serenaders, in 1917. The band's first job was at the True Reformers Hall in Washington, D.C. For five dollars a night (total), they played at dance halls and lodges. During the day, Ellington operated a sign and poster business. He also played with other bands, led by a contractor. When the contractor sent Ellington's band out on a job, one which paid $100, the contractor instructed Ellington to take $10 and bring him the remaining $90. Discovering this aspect of the business, within a short period, Ellington had assembled several bands and was supplying the city with "a band for any occasion."

The Duke's Serenaders trio was made up of Ellington on piano, Otto Hardwick on saxophone, and Sonny Greer on drums

i agree duke ellingtons orchestra though you ll find some other titles [few] like dukes big four] get it [its great] but huge majority was duke ellingtons orchestra

It was the Duke Ellington Orchestra, or sometimes billed as Duke Ellington and His Orchestra.