(Fr.: ‘obsession’).
A term coined by Berlioz to denote a musical idea used obsessively. When in 1830 he applied it to the principal theme of his Symphonie fantastique, it was a new term in the French language. At about the same time Balzac used it in Gobseck to describe an obsessive idea, and it came into use as a clinical term for unreasonable or even criminal obsession. Berlioz used the theme to describe the artist’s obsession with his beloved. In December 1832 Fétis drew attention to the novelty of the idea (Revue musicale, xii, 365–7). The theme recurs in each of the five movements of the symphony and in the first supplies the main thematic material of the Allegro. Subsequently it is transformed to fit the context of the various movements, for example into waltz time for the ball and into the grotesque, distorted dance for the final ‘Ronde du Sabbat’. Berlioz recalled the theme in the sequel to the symphony, Lélio, and another recurrent theme occurs in his Harold en Italie (1834). Many later composers have taken up the idea of a recurrent, obsessive theme in symphonic works.
HUGH MACDONALD