Programme music is music which explicitly describes something or tells a story. Programme music was especially prominent in the 19th century, and the Romantic period, although some programme music was composed earlier.

As early as the Renaissance and Baroque periods, composers wrote music to describe certain events or scenarios. Antonio Vivaldi’s The Four Seasons for example, contained four movements each depicting one season of the year, with the music reflecting singing birds of spring, or snowfall in winter.
It was perhaps Beethoven, with his Symphony No. 6 – the Pastoral – that paved the way for a real surge in popularity of programme music. The symphony musically paints a picture of peaceful countryside life, and would be followed by the likes of Mendelssohn’s Hebrides Overture depicting the Scottish islands, and Berlioz’s Symphonie Fantastique.
Symphonie Fantastique tells an autobiographical story of a man (Berlioz himself) who falls in love with a woman. The women in his story was represented by melody which reoccurrs throughout the piece of music, yet altered slightly on each occasion, much like the leitmotif years later in Wagner’s Ring Cycle or, later still, film music. This was called the idée fixe (French for "fixed idea").

Another key advocate of programme music was Richard Strauss, whose epic works – called Tone Poems or Symphonic Poems - included Ein Heldenleben (another allegedly autobiographical work) and An Alpine Symphony, which dramatically covers an ascent and descent of an alpine mountain, complete with bucolic meadow scenes, moments of real peril, and powerful thunderstorms.