In 1794, Beethoven wrote the following in Franz Clement's memory book: "Be happy, my dear young friend, and come back soon, so that I may hear your delightful, splendid playing again". The 14-year-old violinist was then a prodigy who had already aroused the admiration of many important musicians and aristocrats throughout Europe. Beethoven and Clement later became friends, and it was at Clement's request that Beethoven composed in 1806 his only violin concerto. Apart from being particularly fruitful in terms of output, 1806 was also the year when Beethoven finally acknowledged his deafness. He nevertheless assured his entourage that his loss of hearing "will no longer be an obstacle, even in the field of art". At the first performance of the Violin Concerto on 23 December 1806 at the Theater an der Wien, Beethoven took everyone by surprise. The critics gave very mixed reviews, condemning the "continual uproar" and the work's "lacking continuity". According to legend, the soloist played his part a vista, without any previous rehearsal! The concerto was long considered unplayable and was almost ignored during the three decades following its premiere. This masterpiece ultimately owes its reputation to another young violin prodigy. In 1844, 13-year-old Joseph Joachim brought the work to a triumph in London at a concert conducted by Mendelssohn. From then on, the Hungarian-born violinist made the D major Concerto a centrepiece of his repertoire and brought to the forefront of the stage this work of a new genre, that overturns the relationship between soloist and orchestra.

The Symphonie fantastique is doubly the result of love at first sight. At the age of 24, Berlioz fell in love with Harriet Smithson, an Irish actress who played Ophelia in Shakespeare's Hamlet at the Odéon Theatre in Paris. At about the same time, the French composer discovered Beethoven's symphonies, which gave him a jolt "comparable to the discovery of Shakespeare". Inspired by the revelation of this "new musical world" and driven by his love for Harriet, Berlioz gave way to his overflow of passion in the first of his four symphonies, thus paving the way for the symphonic poem. The composer made no secret of the autobiographical dimension of the work, which he subtitles "Episode in the Life of an Artist". A few days before the premiere of his Symphonie fantastique, on 5 December 1830 at the Paris Conservatory (under François Antoine Habeneck), Berlioz published a detailed program of this work, which is entirely built around the "idée fixe" based on the first theme of the Allegro (Dreams - Passions). This reflection of the woman loved by the artist reappears in each of the next four movements. It can be heard in the second movement's delightful waltz (A ball), the pastoral "Scene in the Countryside" (maybe inspired by Beethoven's "Pastoral" Symphony), the "March to the scaffold" right through to the final "Dream of a Witches' Sabbath", which culminates in an infernal round introduced by a Dies Irae. Berlioz displayed a formidable creative force in this symphony, inventing a dramatic universe without precedent in the field of symphonic music. "Berlioz kept his word: his Symphonie fantastique is a true musical novel," wrote Le Figaro columnist the day after the premiere.