Ellington personally created most of the music played by his orchestra. He often wrote pieces for specific players with distinctive musical styles in his band, such as "Concerto for Cootie" (1940) for fellow musician and trumpeter, Cootie Williams. With the help from American trumpeter James "Bubber" Miley, Ellington often incorporated in his music the jungle effect. This effect was made by placing a plunger at the opening of a brass instrument, therefore, muffling or muting the notes played out. The result sounded like a person wailing, giving the piece a voice-like quality. In "Concerto for Cootie," Cootie Williams does a solo using the jungle effect, making it sound like a voice is singing along. His opening solo is repetitive, going over the same set of notes over and over again. The overall feeling is as if the music is wooing the listener.
Ellington's other innovations include the use of the human voice as an instrument, such as in "Creole Love Call" (1927). He also placed instruments in unusual combinations, illustrated in the piece "Mood Indigo" (1930). When the orchestra performs this piece, three soloists stand out in front of the stage, playing three different instruments. Improvisation was a big part of Ellington's music.
One of Ellington orchestra's signature tunes is "Take the A' Train" (1941). This piece was not written by Ellington but by American composer Billy Strayhorn, who became Ellington's musical collaborator. This piece is very jumpy and light,