In 1827 the composer Hector Berlioz went to see a production of Shakespeare’s Hamlet in Paris.

It was a life-changing experience: he was bowled over by the Bard’s drama and became completely besotted with the Irish actress playing Ophelia, Harriet Smithson. Berlioz went on to write various works inspired by Shakespeare, including Roméo et Juliette and Béatrice et Bénédict, and his infatuation with Smithson inspired his great Symphonie fantastique.

Berlioz's obssession with Smithson grew. He rented rooms near her and sent her letters – but to no avail. So he then embarked on the ultimate romantic gesture, writing an orchestral symphony for her. The first performance of the Symphonie fantastique was arranged for 5 December 1830, to mark her return to Paris, but although the work was well received, she was not present. She didn’t hear the work until two years later.

Symphonie fantastique tells the autobiographical story of the composer’s love for Smithson and his emotional torment. In the opening movement the young musician first sees the woman of his dreams. Her image haunts his imagination, presented as a musical theme, or idée fixe. This is transformed in the following movements, as he experiences a festive party, a stroll in the countryside, opium hallucinations and a witches’ sabbath. For Berlioz, it seems there was no real distinction between the real Smithson and one of Shakespeare’s heroines. He often referred to her as Ophelia, Juliet or Desdemona.

After Smithson missed the 1830 premiere, Berlioz had a fling with pianist Marie-Félicité-Denise Moke leading to a disastrous and brief engagement. When Berlioz returned to Paris in 1832, he stayed at an apartment in Rue Neuve-Saint-Marc and discovered that it had just been vacated by Harriet Smithson. Spurred on by his renewed obsession he arranged a second performance of the Symphonie fantastique. This time the actress was in attendance and she was won over by the work. Despite opposition from both families the couple were married in October 1833.

Unfortunately, the marriage didn’t work out. Their son Louis was born the following year but the couple separated. Smithson’s career was on the rocks and she was an alcoholic. Berlioz took up with a singer, Marie Recio, and they married after Smithson's death in 1854.

Symphonie fantastique has an enduring popularity and gives us a musical memoir of Berlioz’s infatuation with Smithson. 'Love cannot express the idea of music, while music may give an idea of love,' wrote the composer.

Neil McKim