Enescu’s published output extends to only 33 opus numbers, though several of these are very large-scale works (the three symphonies and Oedipe). The demands of a busy career as a performer were not the only reason for this comparative paucity of finished output. Enescu was also an obsessive perfectionist: many of his published works were repeatedly redrafted before their first performances, and revised several times thereafter. Moreover, as recent research has made increasingly clear, the works which he did allow to be published were merely the tip of a huge submerged mass of manuscript work-in-progress (the bulk of which is held by the Enescu Museum, Bucharest). The leading authority on these manuscripts, Clemansa Firca, suggests that there may be ‘several hundred’ compositions in varying degrees of rough draft or near-completion. In some cases, too, the same thematic material would be re-worked in manuscript for decades before emerging in one of the published works.

Such inner continuities are obscured, however, by the striking stylistic changes which took place during Enescu’s seven decades as a composer. His first student works (from Vienna and his early Paris years) show the heavy influence of Schumann and Brahms. French influence comes to the fore with his Second Violin Sonata (1899), where the fluid piano textures and delicate combination of chromaticism and modal cadences are strongly reminiscent of Gabriel Fauré. This sonata, written at the age of 17, was later described by Enescu as the first work in which he felt he was ‘becoming myself’. Yet, for the next 15 years or more, he continued to switch eclectically between a variety of stylistic idioms. His Octet for Strings (1900) combines rich late-Viennese chromaticism with ferocious contrapuntal energy; the First Symphony (1905) is an ambitious and sweepingly Romantic work with an explicit debt to Tristan und Isolde in the slow movement; but interspersed with these compositions were a number of neo-classical or neo-Baroque works, including the First Orchestral Suite (1903), the Second Piano Suite (1903) and the limpid Sept chansons de Clément Marot (1908), in which the piano part imitates, at times, the sonorities of lute music. The culmination of his series of neo-classical works was the Second Orchestral Suite (1915), whose bustling mock-Baroque figurations foreshadow Prokofiev’s Classical Symphony (1917) and Stravinsky’s Pulcinella (1919). Yet, almost contemporaneously, Enescu’s dense and intricate Second Symphony (1914) explored the harmonic world of Richard Strauss’s Salome and Elektra.

Traditional accounts of Enescu’s musical development place great emphasis on the elements of Romanian folk music which appear in his works at an early stage – above all, in the Poème roumain (1897) and the two Romanian Rhapsodies (1901). (These latter works were to become an albatross round Enescu’s neck: later in his life he bitterly resented the way they had dominated and narrowed his reputation as a composer.) But he quickly tired of the limited possibilities offered by the task of ‘setting’ Romanian songs and dances; as he remarked in 1924, the only thing a composer could do with an existing piece of folk music was ‘to rhapsodize it, with repetitions and juxtapositions’.

The real significance of his Romanian folk-heritage would emerge later in the growth of Enescu’s musical language, as he searched for new ways of developing, and combining, pure melodic lines. Particularly influential here was the doina, a type of meditative song, frequently melancholic, with an extended and flexible line in which melody and ornamentation merge into one. (This was the type of song for which Béla Bartók had coined the phrase parlando rubato.) The melodic line was, for Enescu, the vital principle of music: as he wrote in his autobiography, ‘I’m not a person for pretty successions of chords … a piece deserves to be called a musical composition only if it has a line, a melody, or, even better, melodies superimposed on one another’. His urge to superimpose melodies led, in several early works, to some exorbitant uses of cyclical form: in the last movement of the Octet for Strings, for example, all the melodic elements of the work return, to be piled one on top of another. In his mature works, however, Enescu made increasing use of the less mechanically contrapuntal, more organic technique of heterophony – a form of loose melodic superimposition which was also rooted in Romanian folk music.

Some elements of Enescu’s mature style began to emerge at the end of World War I, with the completion of the Third Symphony (1918) and the First String Quartet (1920). Both works display an organicist style of development, in which germinal themes, intervals and note-patterns are constantly adapted and recombined. As Enescu worked on his opera Oedipe during the 1920s, this method lent itself naturally to the elaboration of leitmotifs: one modern study (by Octavian Cosma) has identified 21 such motifs in the work, although their functioning is so germinal and cellular that it is possible for listeners to experience the whole work without being aware of the presence of leitmotifs at all. Another feature of the opera is the minutely detailed orchestration, which frequently makes use of solo instruments within the orchestral texture. This concentration on individual voices may help to explain why the output of his final decades is dominated by chamber music. Only two major orchestral works were completed after Oedipe: the Third Orchestral Suite (1938) and the symphonic poem Vox Maris (c1954). (Three works left in unfinished draft have, however, been completed recently by Romanian composers: the Caprice roumain for violin and orchestra (1928), completed by Cornel Taranu, and the Fourth (1934) and Fifth (1941) symphonies, completed by Pascal Bentoiu.)

The great series of chamber works which crowns Enescu’s output begins with the Third Violin Sonata (1926), and includes the Piano Quintet (1940), Second Piano Quartet (1944), Second String Quartet (1951) and Chamber Symphony (1954). Enescu stays within the bounds of late-Romantic tonality and classical forms but transmutes both into a very personal idiom; ceaseless motivic development is woven into elaborate adaptations of sonata form, variation-sequences and cyclical recombinations. Romanian folk elements are also present, sometimes in the form of percussive Bartókian dances, but the most characteristic use of folk music here involves the meditative doina. In several works (the Third Orchestral Suite, the Impressions d’enfance for violin and piano (1940) and the Third Violin Sonata, as commented on by Enescu) the use of such folk elements was linked to the theme of childhood reminiscence: what Enescu aimed at was not the alienating effect of quasi-primitivism which modernists sought in folk music (Stravinsky, for example), but, on the contrary, a childlike sense of immediacy and intimacy. That, indeed, is the special character of many of his finest works.