What musical composition presents a theme or idea from a non-musical source?

One notable musical composition that presents a theme from a non-musical source is "Symphonic Variations" by César Franck. This piece is inspired by the concept of variation and transformation, reflecting the idea of personal growth and development. The music captures the essence of its non-musical inspiration through intricate themes and variations that convey emotional depth and complexity. This approach highlights how composers can translate abstract ideas into a musical form, creating a rich auditory experience.