[1] In Onslow's own brief autobiography (written in the third person) he comments that in his childhood, "music studies formed but a secondary part of his education" but names Jan Ladislav Dussek and Johann Baptist Cramer amongst his piano teachers.
[1] However, other research indicates he may not have studied with Dussek until 1797–1798 in Hamburg, where his family was living in exile after his father had become involved in counter-revolutionary activities in France.
This research also indicates that there is no evidence to support the suggestions sometimes made that Onslow at any time visited Vienna, or that he met, or studied, there with Ludwig van Beethoven.
[2] Onslow states in his autobiography that his attitude to music was transformed by his experience of hearing the overture to Étienne Méhul's opera Stratonice in Paris in 1801.
In Onslow's own later words: "On hearing this piece, I experienced so lively an emotion in the depths of my soul that I sensed myself at once penetrated by feelings previously unknown to me; even today this moment is present in my thought.
[5] In 1824 and 1827 his first two operas, L'Alcalde de la vega and Le colporteur, were premiered at the Théâtre Feydeau in Paris under the auspices of the Opéra-Comique.
[1] In 1825 in Paris he met the 16-year-old Felix Mendelssohn, who enjoyed a performance of one of Onslow's quartets but was surprised that he was not aware of Beethoven's opera Fidelio.
[6] Onslow was an early enthusiast of the music of Hector Berlioz, whose Eight scenes from Faust (1829) and overture Les francs-juges (1830) he praised.
38 (his fifteenth), he was very seriously wounded in a hunting accident, which left him partially deaf in one ear; completing the quintet in the aftermath, he named the final movements "Fever", "Convalescence" and "Recovery".
42, and continued to maintain close relations with leading London musicians including John Ella and George Frederick Anderson.
In 1839 Onslow founded the "Société Philharmonique de Clermont" in which the émigré Polish violinist Alexandre Tarnowski was very active.
At the instigation of Tarnowski, Onslow also hosted in Clermont-Ferrand the Polish-Jewish xylophonist and rival of Josef Gusikov, Sankson Jakubowski.
[1] Invited to the Aachen music festival in 1846, in the following year, on what may have been his last journey outside France, Onslow conducted his Fourth Symphony in Cologne, at the Niederrheinisches Musikfest.
Fétis complained in 1830: "Nature worked in vain to have a Haydn or a Beethoven born in France; such talent was better concealed in the capital than are diamonds deep in the earth.
The lack of encouragement for instrumental music, a taste for futilities, and other secondary causes which it would be too tedious to detail, have left us insensible to anything but fantasies, variations and other trivia.