19th- and 20th-century genre of program music for orchestra. Symphonic poems are generally in one movement and are usually associated with ideas from paintings, poems, dramas, natural landscapes, or other extramusical sources. Such ideas may range from literal portrayal, as of a locomotive in Pacific 231 (1923) by Arthur Honegger, to the nonspecific and evocative, as in Les préludes (1854) by Franz Liszt.

The impulse toward the extramusical was an important part of musical romanticism. Its leading early proponents were Hector Berlioz and Liszt, who was influenced by Berlioz and who originated the term symphonic poem.

In contrast to the ideal form of 18th-century music, based on a purely musical sequence of exposition, development, and recapitulation, the form of the symphonic poem is derived from the character or “plot” of the extramusical program. Following the example of Berlioz and Liszt, later composers such as Antonín Dvoÿrák, Jean Sibelius, Bedÿrich Smetana, Richard Strauss, and Peter Tchaikovsky provided continuity and cohesion in their symphonic poems by using one or more recurring themes (often given symbolic meaning), which they transformed and changed as the narrative or evocative demands of the program required. The symphonic poem’s exploitation of harmony and instrumental color for expressive purposes led to innovations in harmonic progressions and in the uses and combinations of instruments. In the 20th century fewer symphonic poems were written, as composers placed new emphasis on concise, abstract musical forms and smaller instrumental ensembles.