Liszt was a vigorous proponent of program music: instrumental music that is explicitly connected to something external, such as a story, a scene, or a feeling. In his era many listeners and commentators liked to devise their own “poetic” interpretations of music of all kinds, so Liszt explained that when the composer supplied a program, he not only spelled out his own interpretation, but also guarded against listeners inventing incorrect ones of their own. Program music was by no means a new invention—one can cite many earlier examples, such as Beethoven’s Pastorale Symphony and even a viola da gamba piece by the French baroque composer Marin Marais that depicts a surgical opera­tion—but it was especially popular in the middle of the 19th century. It was also controversial; the Austrian critic Eduard Hanslick and his supporters argued for the supremacy of “absolute music,” which sought to achieve its effect in a more abstract way, without reference to anything outside the music itself.

A high percentage of Liszt’s piano pieces could be classified as program music, but in this sense he may have been more influential as an orchestral composer, for he wrote thirteen single-move­ment works called “symphonic poems”—the term is Liszt’s own—that established a new genre, one that remained popular with composers into the early 20th century. Liszt’s symphonic poems were inspired by a variety of literary, artistic, historical, and religious sources. Some of these are somewhat abstract and philosophical in nature, while others depict extremely concrete subjects, such as a battle between the Romans and the Huns in the year 451. Despite their immense influence, most of Liszt’s symphonic poems have fallen out of the standard repertoire; the exception is Les Préludes, which is performed regularly to this day. It draws its inspiration from a poem by Alphonse de Lamartine, but it was Hans von Bülow who was responsible for the preface that was published with the score. It begins by asking, “What else is our life, but a series of preludes to that unknown Hymn, the first and solemn note of which is intoned by Death?” The music is dominated by a single theme, which appears in a variety of guises that apparently portray the phases of life, death, and the afterlife.