Richards, a pivotal figure in mid-20th century American jazz arranging, significantly shaped the sound of big band music. Known for his sophisticated harmonic language and innovative use of counterpoint, his arrangements elevated the standard repertoire. He collaborated extensively with leading orchestras of the era, crafting bespoke charts that showcased individual soloists while maintaining a cohesive ensemble sound. Richards' contributions extended beyond mere transcription; he reimagined existing melodies, injecting them with fresh rhythmic and harmonic vitality, and composed original works that became staples in the jazz band canon, influencing generations of arrangers.