Nelson Riddle was quite possibly the greatest arranger in the history of American popular music. Over the course of his long and distinguished career, he was also a popular soundtrack composer, a conductor, a trombonist, and an occasional hitmaker in his own right. He worked with many of the major pop vocalists of his day, but it was his immortal work with Frank Sinatra, particularly on the singer's justly revered Capitol concept albums, that cemented Riddle's enduring legacy. Riddle was a master of mood and subtlety, and an expert at drawing out a song's emotional subtext. He was highly versatile in terms of style, mood, and tempo, and packed his charts full of rhythmic and melodic variations and rich tonal colors that blended seamlessly behind the lead vocal line. He often wrote specifically for individual vocalists, keeping their strengths and limitations in mind and pushing them to deliver emotionally resonant performances. As such, Riddle was perfectly suited to the task of framing vocal interpreters, as opposed to just singers; he was most in sync with the more nuanced and artistically ambitious vocalists, like Sinatra. Riddle knew how to lay back and bring certain lyrics or vocal subtleties to the forefront, and how to add countermelodies that emphasized other lyrics, or made important transitions. He could draw the listener in with catchy embellishments, challenge them with adventurous harmonies, and build to climaxes that faded into surprisingly restrained endings. In short, Riddle was everything a top-notch singer could ask for.