George Gershwin's "A Foggy Day" receives a swinging treatment on the 1956 Verve album Ella and Louis, with Louis Armstrong contributing a half-chorus trumpet solo over the 34-bar ABAC form at 113 beats per minute in C major. Armstrong's solo is a concentrated display of the melodic invention and rhythmic authority that first revolutionized jazz in the 1920s, his playing still vital and creative more than three decades into his career. The Gershwin composition, originally written for the 1937 film A Damsel in Distress, is one of the most frequently performed songs in jazz, its chromatic melody and sophisticated harmony providing rich material for improvisation. Fitzgerald and Armstrong approach the song with the easy familiarity of artists completely at home with this repertoire, their vocal exchanges characterized by warmth, humor, and mutual respect. The Oscar Peterson Quartet, with Peterson on piano, Herb Ellis on guitar, Ray Brown on bass, and Buddy Rich on drums, drives the performance with a swing feel of effortless precision. Producer Norman Granz's genius in conceiving the Ella and Louis sessions lay in recognizing that these two artists shared a deep love of great songs and possessed the vocal and instrumental gifts to do them full justice.