' (Fantastic Symphony: Episode in the Life of an Artist … in Five Sections) Op. 14, is a programmatic symphony written by Hector Berlioz in 1830. The first performance was at the Paris Conservatoire on 5 December 1830, conducted by François-Antoine Habeneck.

Berlioz wrote semi-autobiographical programme notes for the piece that allude to the romantic sufferings of a gifted artist who has poisoned himself with opium because of his unrequited love for a beautiful and fascinating woman (in real life, the Shakespearean actress Harriet Smithson, who in 1833 married Berlioz). The composer, who revered Beethoven, followed the latter's unusual addition in the Pastoral Symphony of a fifth movement to the normal four of a classical symphony. The artist's reveries take him to a ball and to a pastoral scene in a field, which is interrupted by a hallucinatory march to the scaffold, leading to a grotesque satanic dance (Witches' Sabbath). Within each episode, the artist's passion is represented by a recurring theme called the .

The symphony has long been a favourite with audiences and conductors. In 1831 Berlioz wrote a sequel, Lélio, for actor, soloists, chorus, piano and orchestra. Franz Liszt made a piano transcription of the score that was first recorded by Idil Biret in 1979.

Overview

thumb|upright=1.3|alt=musical score showing long phrase, covering 41 bars or measures|The idée fixe theme, which recurs in various guises in each of the five movements

The ' is a piece of programme music that tells the story of a gifted artist who, in the depths of hopelessness and despair because of his unrequited love for a woman, has poisoned himself with opium. The symphony tells the story of the artist's drug-fuelled hallucinations, beginning with a ball and a scene in a field and ending with a march to the scaffold and a satanic dream. The artist's passion is represented by an elusive theme which Berlioz called the idée fixe, a contemporary medical term also found in literary works of the period. It is defined by the Dictionnaire de l'Académie française as "an idea that keeps coming back to mind, an obsessive preoccupation".

Berlioz provided his own preface and programme notes for each movement of the work. They exist in two principal versions: one from 1845 in the first edition of the work and the second from 1855. These changes show how Berlioz downplayed the programmatic aspect of the piece later in life.

The first printing of the score, dedicated to Nicholas I of Russia, was published in 1845. In it, Berlioz writes:

thumb|[[George Clint's portrait of Harriett Smithson, the inspiration for the symphony]]

In 1855 Berlioz writes:

Berlioz wanted people to understand his compositional intention, as the story he attached to each movement drove his musical choices. He said, "For this reason I generally find it extremely painful to hear my works conducted by someone other than myself."

Inspiration

Attending a performance of Shakespeare's Hamlet on 11 September 1827, Berlioz fell in love with the Irish actress Harriet Smithson, who played the role of Ophelia. His biographer Hugh Macdonald writes of Berlioz's "emotional derangement" in obsessively pursuing her, without success, for several years. She refused even to meet him. He sent her numerous love letters, all of which were unanswered.

The Symphonie fantastique reflects his obsession with Smithson. She did not attend the premiere, given at the Paris Conservatoire on 5 December 1830, but she heard Berlioz's revised version of the work in 1832 at a concert that also included its sequel, Lélio, which incorporates the same idée fixe and some spoken commentary. She finally appreciated the strength of his feelings for her. The two met shortly afterwards and began a romance that led to their marriage the following year.

Instrumentation

The score calls for an orchestra of about 90 players:

;Woodwinds

:

:

:

:4 bassoons

;Brass

:4 horns

:2 cornets

:2 trumpets

:3 trombones

:2 ophicleides

;Percussion

:

:cymbals

:snare drum (used only in movement IV)

:bass drum

:

;Strings

:at least 6 harps (used only in movement II)

:at least 15 1st violins

:at least 15 2nd violins

:at least 10 violas

:at least 11 celli

:at least 9 double basses

Movements

thumb|Title page of the manuscript score|upright=1.2

Following the precedent of the Pastoral Symphony of Beethoven, whom Berlioz revered, the symphony has five movements, instead of four as was conventional for symphonies of the time.

Each movement depicts an episode in the protagonist's life that is described by Berlioz in the notes to the 1845 score. These notes are quoted (in italics) in each section below.

I. "Rêveries – Passions" (Daydreams – passions)

Structurally the movement derives from the traditional sonata form found in all classical symphonies. A long, slow introduction leads to an Allegro in which Berlioz introduces the idée fixe as the main theme of a sonata form comprising a short exposition followed by alternating sections of development and recapitulation. The idée fixe begins:

The theme was taken from Berlioz's scène lyrique "Herminie", composed in 1828.

II. "Un bal" (A ball)