1773 in music
- January 18 – The first opera performance in the Swedish language, Thetis and Phelée, starring Carl Stenborg, Elisabeth Olin and Hedvig Wigert in Bollhuset in Stockholm, Sweden, marks the establishment of the Royal Swedish Opera.
- February – Joseph Leutgeb tours Italy with Leopold and Wolfgang Amadeus Mozart.
- May 28 – The opera Alceste by Anton Schweitzer with German language libretto by poet Christoph Martin Wieland is premièred by the Seyler Theatre Company at the Hoftheater Weimar, pioneering a German operatic style.
- July 14 – Wolfgang Amadeus Mozart and his father Leopold go to Vienna in search of work.
- Composer James Hook vacates his post at Marylebone Gardens in London.
- Pasquale Anfossi – Demofoonte
- Domenico Cimarosa – La finta parigina
- Joseph Haydn – L'infedeltà delusa; Philemon und Baucis
- Andrea Luchesi – L'Inganno Scoperto, overo Il Conte Caramella (libretto by Carlo Goldoni)
- Anton Schweitzer – Alceste (libretto by Christoph Martin Wieland)
- Johann Albrechtsberger – Concerto for Harp in C major
- Samuel Arnold – The Prodigal Son (oratorio)
- Wolfgang Amadeus Mozart – Symphony No. 25 in G minor
- Giovanni Battista Sammartini – Six String Quintets
- Carl Ditters von Dittersdorf – La Liberatrice del Popolo Giudaico nella Persia, o sia l’Esther (oratorio)
- January 4 – Johann Peter Heuschkel, composer (died 1853)
- March 7 – Tommaso Marchesi, composer (died 1852)
- May 26 – Hans Georg Nägeli, composer (died 1836)
- July 6 – Wenzel Thomas Matiegka, composer (died 1830)
- September 24 – Johann Philipp Christian Schulz, composer (died 1827)
- October 23 – Pietro Generali, composer (died 1832)
- December 9 – Marianne Ehrenström, musician and writer (died 1867)
- December 24 – Joseph Wölfl, pianist and composer (died 1812)
- exact date unknown
- April 11 – Carlo Grua, composer (b. c. 1700)
- April 12 – Elizabeth Young, operatic contralto and actress (b. c. 1730)
- May 24 – Jan Zach, violinist, organist and composer (b. 1699)
- July 12 – Johann Joachim Quantz, flautist and composer (b. 1697)
- August 25 – Franz Nikolaus Novotny, organist and composer (born 1743)
- date unknown