This is one of a series of postings of important classical music dates, from the 17th century to the present. Included are the date and location of the birth and death of composers, and the premiere date and location of the first public performance of works. When the premiere date and location is unknown, the date or year of completion of the work is given. Though reasonably comprehensive, this is a subjective list, so the choice of composers and works is mine. If you find any errors, or if you can offer a premiere date and location for a work where only the completion date or year is listed, please post a comment here.
1840
May 7 – Pyotr Ilyich Tchaikovsky (1840-1893) was born in Votkinsk, Russia
September 30 – Johan Svendsen (1840-1911) was born in Oslo, Norway
1841
January 18 – Emmanuel Chabrier (1841-1894) was born in Ambert, France
March 31 – Symphony No. 1 in B♭ major, op. 38, “Spring”, by Robert Schumann (1810-1856) was first performed in Leipzig, Germany
September 8 – Antonín Dvořák (1841-1904) was born in Nelahozeves, Czech Republic
October 17 – Symphony No. 5 in B♭ major, D. 485, by Franz Schubert (1797-1828) was first performed in Vienna, Austria
December 6 – The 1st version of Symphony No. 4 in D minor, op. 120 (much preferred by Johannes Brahms) by Robert Schumann (1810-1856) was first performed in Leipzig, Germany
1842
Louise Farrenc (1804-1875) completed Symphony No. 1 in C minor, op. 32
March 3 – Symphony No. 3 in A minor, op. 56, “Scottish”, by Felix Mendelssohn (1809-1847) was first performed in Leipzig, Germany
March 9 – Sinfonia from the opera Nabucco by Giuseppe Verdi (1813-1901) was first performed in Milan, Italy
May 12 – Jules Massenet (1842-1912) was born in Saint-Étienne, France
December 9 – Ruslan and Lyudmila, opera by Mikhail Glinka (1804-1857), was first performed in Saint Petersburg, Russia
1843
January 8 – Piano Quintet in E♭ major, op. 44 by Robert Schumann (1810-1856) was first performed in Leipzig, Germany
June 15 – Edvard Grieg (1843-1907) was born in Bergen, Norway
1844
Frédéric Chopin (1810-1849) completed Piano Sonata No. 3 in B minor, op. 58
February 21 – Charles-Marie Widor (1844-1937) was born in Lyon, France
March 18 – Nikolai Rimsky-Korsakov (1844-1908) was born in Tikhvin, Russia
1845
Charles Auguste de Bériot (1802-1870) completed the Violin Concerto No. 8 in D major, op. 99
Mikhail Glinka (1804-1857) completed Capriccio brillante on the Jota aragonesa, Spanish Overture No. 1
March 13 – Violin Concerto in E minor, op. 64, by Felix Mendelssohn (1809-1847) was first performed in Leipzig, Germany
May 12 – Gabriel Fauré (1845-1924) was born in Pamiers, France
December 4 – Piano Concerto in A minor, op. 54 by Robert Schumann (1810-1856) was first performed in Dresden, Germany
1846
November 5 – Symphony No. 2 in C major, op. 61 by Robert Schumann (1810-1856) was first performed in Leipzig, Germany
1847
Louise Farrenc (1804-1875) completed Symphony No. 3 in G minor, op. 36
Frédéric Chopin (1810-1849) completed Waltz in C♯ minor, op. 64, no. 2
November 4 – Felix Mendelssohn (1809-1847) died in Leipzig, Germany
1849
Robert Schumann (1810-1856) completed the Romances and Ballads, op. 75, for SATB choir a cappella
March – Robert Schumann (1810-1856) completed the Romances, op. 69, for female voices (SSAA) a cappella
March – Robert Schumann (1810-1856) completed the Romances, op. 91, for female SSAA choir a cappella
October 17 – Frédéric Chopin (1810-1849) died in Paris, France
December 8 – Sinfonia from the opera Luisa Miller by Giuseppe Verdi (1813-1901) was first performed in Naples, Italy
1850s→