Kenton Dectet #133X was a pivotal, albeit lesser-known, American jazz arranger active during the mid-20th century, primarily from the late 1940s through the 1960s. Influenced by the progressive jazz movement, their style blended intricate harmonies and sophisticated counterpoint with a powerful, brass-heavy sound, reminiscent of the Stan Kenton Orchestra's "Innovations in Modern Music" era. Dectet #133X was renowned for their innovative voicings for large ensembles, pushing the boundaries of big band orchestration. While specific works are difficult to pinpoint due to the era's often uncredited arrangements, their contributions are evident in the evolving soundscapes of numerous West Coast jazz recordings, shaping the harmonic and textural richness of the era's large jazz ensembles.