This is a list of music-related events in 1804.
January 1 - Johann Nepomuk Hummel's Concerto for trumpet and orchestra receives its première in Vienna, in the presence of Nicholas II, Prince Esterházy.
January 23 - François-Adrien Boieldieu becomes musical director at the court of Tsar Alexander I of Russia.
February 20 - Giovanni Paisiello is appointed Maestro di Cappella at Naples.
April 22 - Twelve-year-old Gioachino Rossini gives a concert at Imola.
May 8 - Seventeen-year-old Carl Maria von Weber becomes Kapellmeister at Breslau in Silesia.
May 14 - Napoleon proclaims himself emperor, causing Beethoven to tear up the title page of his recently-completed Symphony No. 3 and rename it the Eroica.
September 18 - Composer Muzio Clementi marries 19-year-old pianist Caroline Lehmann, the daughter of Johann Georg Lehmann, director of the Royal Opera, Berlin. There is a 33-year age gap between bride and groom.
Nicolas Dalayrac is awarded the Légion d'honneur.
Ludwig van Beethoven
Piano Sonata No. 22 in F major written
Opus 85 Christus am Ölberge (completed)
Symphony No. 2 (published)
Jan Ladislav Dussek - Fantasia and Fugue for piano
Anton Eberl - Symphony in D minor, Op. 34
Johann Nepomuk Hummel - Variations for piano op.15
Leopold Kozeluch - Three Piano Sonatas
Louis Spohr – Concerto for Violin no 2 in D minor, Op. 2
François-Adrien Boieldieu - Aline, reine de Golconde
Pierre Gaveaux – Le Mariage inattendu
Adalbert Gyrowetz – Selico
Ferdinando Paer – Leonora
Gaspare Spontini – Milton
Georg Joseph Vogler - Samori
March 14 – Johann Strauss I, Austrian composer (d. 1849)
March 30 – Salomon Sulzer, Austrian Jewish composer (d. 1890)
May 31 – Louise Farrenc, born Jeanne-Louise Dumont, French pianist and composer (d. 1875)
June 1 – Mikhail Glinka, Russian composer (d. 1857)
July 14 - Julius Schuberth, German author and publisher, founder of Schuberth & Co. (d. 1875)
August 19 – Christina Enbom, Swedish operatic soprano (d. 1880)
October 1 - Eduard Sobolewski, Polish-American violinist, composer and conductor (may have been born in 1808; d. 1872)
November 27 – Sir Julius Benedict, German-born conductor and composer (d. 1885)
date unknown – Ferdinand Giovanni Schediwy, Czech-born organist, conductor and composer (d. 1877)
March 29 (or 30) – Ivan Khandoshkin, violinist and composer (b. 1747)
June 16 – Johann Adam Hiller, conductor, composer and music writer (b. 1728)
August 24 – Valentin Adamberger, operatic tenor (b. 1740)
November 5 – Maria Anna Adamberger, actress and singer, wife of Valentin Adamberger (b. 1752)
November 19 – Pietro Guglielmi, composer (b. 1728)
date unknown
Gioacchino Cocchi, opera composer (b.c.1720)
Marie Louise Marcadet, actress and singer (b. 1758)
Lorenzo Quaglio, stage designer (b. 1730)
Giovanni Valentini, composer, poet and painter (b. c. 1730)
Abraham Wood, early American composer (b. 1752)
1804 in music Wikipedia (Text) CC BY-SA