Sid Engel, an American jazz arranger active from the 1940s through the 1960s, was a significant, albeit often uncredited, contributor to the big band sound. Known for his sophisticated harmonic voicings and innovative sectional writing, Engel’s arrangements blended swing era exuberance with emerging bebop complexities. He frequently collaborated with prominent bandleaders like Artie Shaw and Stan Kenton, crafting intricate charts that showcased their ensembles' virtuosity. His contributions helped define the evolving sound of post-war jazz orchestras, influencing a generation of arrangers with his distinctive approach to orchestration and melodic development.