Ian Polster, an American jazz arranger and composer active from the mid-20th century, significantly shaped the sound of big band jazz. Known for his sophisticated harmonic language and innovative voicings, Polster's arrangements infused traditional swing with modern jazz sensibilities. He collaborated with numerous prominent orchestras, including those led by Stan Kenton and Woody Herman, contributing intricate and challenging charts that became staples of the jazz repertoire. His work is particularly noted for its expansion of the brass and woodwind sections' capabilities, pushing boundaries in ensemble writing and influencing generations of jazz arrangers with his distinctive blend of complexity and melodicism.