Incidental music ismusic in aplay,television program,radio program,video game, or some other presentation form that is not primarily musical. The term is less frequently applied tofilm music, with such music being referred to instead as thefilm score orsoundtrack.

Incidental music is oftenbackground music, and is intended to add atmosphere to the action. It may take the form of something as simple as a low, ominous tone suggesting an impending startling event or to enhance the depiction of a story-advancing sequence. It may also include pieces such asovertures, music played during scene changes, or at the end of anact, immediately preceding an interlude, as was customary with several nineteenth-century plays. It may also be required in plays that havemusicians performing on-stage.

The phrase "incidental music" is from the GermanInzidenzmusik, which is defined in theMethuen Drama Dictionary of the Theatre as "music that is specifically written for a play but does not form an integral part of the work".^[1] The use of incidental music dates back to ancientGreek drama and possibly before the Greeks.^[2] A number ofclassicalcomposers have written incidental music for various plays, with the more famous examples includingHenry Purcell'sAbdelazer music,George Frideric Handel'sThe Alchemist music,Joseph Haydn'sIl distratto music,^{[citation needed]}Wolfgang Amadeus Mozart'sThamos, King of Egypt music,Ludwig van Beethoven'sEgmont music,^[3]Carl Maria von Weber'sPreciosa music,^{[citation needed]}Franz Schubert'sRosamunde music,^[4]Felix Mendelssohn'sA Midsummer Night's Dream music,Robert Schumann'sManfred music,^[3]Georges Bizet'sL'Arlésienne music,^[5] andEdvard Grieg'sPeer Gynt music.^[6] Parts of all of these are often performed in concerts outside the context of the play. Vocal incidental music, which is included in the classical scores mentioned above, should not be confused with the score of aBroadway orfilm musical, in which the songs often reveal character and further the storyline. Since the score of a Broadway or film musical is what actually makes the work amusical, it is far more essential to the work than mere incidental music, which nearly always amounts to little more than a background score; indeed, many plays have no incidental music whatsoever.

Some early examples of what were later called incidental music are also described assemi-operas, quasi-operas,masques,vaudevilles^{[citation needed]} andmelodramas.^[7]

The genre of incidental music does not extend to pieces designed for concert performance, such as overtures named after a play, for example, Beethoven'sCoriolan Overture (written forHeinrich Joseph von Collin's tragedy), orTchaikovsky'sRomeo and Juliet fantasy-overture.

Incidental music is also found in religious ceremony, often when officiants are walking from place to place. (This is distinguished from hymns, where the music is the focus of worship.) Incidental music is also used extensively in comedy shows for a similar purpose: providing mild entertainment during a dull transition. Famous comedy incidental musicians includePaul Schaffer,Max Weinberg, andJon Batiste.

Modern composers of incidental music includePierre Boulez,Lorenzo Ferrero,Irmin Schmidt,Ilona Sekacz,John White, andIannis Xenakis.

Anoverture is incidental music that is played usually at the beginning of a film, play, opera, etc., before the action begins. It may be a complete work of music in itself or just a simple tune. In some cases it incorporates musical themes that are later repeated in other incidental music used during the performance.

Atheme song is a work that represents the performance and is often played at the beginning or end of the performance. Elements of the theme may be incorporated into other incidental music used during the performance. In films, theme songs are often played duringcredit rolls. Alove theme is a special theme song (often in various modified forms) that accompanies romantic scenes involving the protagonists of a performance.

Theme songs are among the works of incidental music that are most commonly released independently of the performance for which they were written, and occasionally become major successes in their own right.

Anunderscore is a soft soundtrack theme that accompanies the action in a performance. It is usually designed so that spectators are only indirectly aware of its presence. It may help to set or indicate the mood of a scene.

Astinger is a very brief instant of music that accompanies a scene transition in a performance. Often the stinger marks the passage of time or a change in location. Stingers were used frequently in the American television seriesFriends, as an example, to mark scene changes.^{[8][unreliable source?]}

Short sequences of recorded music calledloops are sometimes designed so that they can be repeated indefinitely and seamlessly as required to accompany visuals. These are often used as background music in documentary and trade films.

• Diegesis, sections on the narrative uses of music in film and theatre
• Plays with incidental music
• Program music

• Lamothe, Peter. (2008).Theater music in France, 1864–1914 (Thesis). The University of North Carolina at Chapel Hill.ProQuest 304547910.
• Lubbock, Mark (March 1957)."Music Incidental to a Play".The Musical Times.98 (1369):128–131.doi:10.2307/936528.JSTOR 936528.
• Skinner, Frank.Underscore: A Combination Method-Text-Treatise on Scoring Music for Motion Picture Films or T.V. Hollywood, CA: Skinner Music Company, 1950.https://archive.org/details/skinner-frank.-underscore.-hollywood-ca-skinner-music-company-1950.

• Harris, Steve.Film, Television, and Stage Music on Phonograph Records: a Discography. Jefferson, N.C.: McFarland & Co., 1988.ISBN 0-89950-251-2

• The Foresters Web Opera – Score bySir Arthur Sullivan for a play byAlfred, Lord Tennyson, with additional music arranged by persons unknown. Available online in an extremely complete state, down to the shortest trumpet fanfare, and thus an extremely useful example of Victorian incidental music.