Editing Trombone (section)

=== Classical period ===
The construction of the trombone did not change very much between the Baroque and Classical period, but the bell became slightly more flared. [[Christoph Willibald Gluck]] was the first major composer to use the trombone in an opera overture, in the opera ''[[Alceste (Gluck)|Alceste]] ''(1767). He also used it in the operas ''[[Orfeo ed Euridice]]'', ''[[Iphigénie en Tauride]] ''(1779), and ''[[Echo et Narcisse]]''.

Early Classical composers occasionally included concertante movements with alto trombone as a solo instrument in [[Divertimento|divertimenti]] and [[Serenade|serenades]]; these movements are often extracted from the multi-movement works and performed as standalone alto trombone concerti. Examples include the Serenade in E{{Music|flat}} (1755) by [[Leopold Mozart]]<ref>{{cite web |last1=March |first1=Ivan |title=Albrechtsberger; Mozart, L.: Trombone Concertos |url=http://www.gramophone.co.uk/review/albrechtsberger-mozart-l-trombone-concertos |website=Gramophone}}</ref> and Divertimento in D major (1764)<ref>{{cite web |title=Haydn, M.: Concerto per Trombone Alto in D |url=http://www.stretta-music.at/haydn-concerto-per-trombone-alto-in-d-nr-675861.html |website=Stretta Music}}</ref> by [[Michael Haydn]]. The earliest known independent trombone concerto is probably the Concerto for Alto Trombone and Strings in B{{Music|flat}} (1769)<ref>{{cite web |title=Albrechtsberger, J.G.: Concerto per trombone alto ed archi |url=http://www.stretta-music.at/albrechtsberger-concerto-per-trombone-alto-ed-archi-nr-198464.html |website=Stretta Music}}</ref> by [[Johann Georg Albrechtsberger]].

[[Wolfgang Amadeus Mozart|Mozart]] used the trombone in operas (notably in scenes featuring the Commendatore in ''[[Don Giovanni]]'') and in sacred music. The prominent solo part in the ''Tuba Mirum'' section of his [[Requiem (Mozart)|Requiem]] became a staple audition piece for the instrument. Aside from solo parts, Mozart's orchestration usually features a trio of alto, tenor and bass trombones, doubling the respective voices in the choir. The earliest known symphony featuring a trombone section is Symphony in C minor by [[Anton Zimmermann]].<ref>{{cite web |last1=Threasher |first1=David |title=A. Zimmermann: Symphonies (Ehrhardt) |url=http://www.gramophone.co.uk/reviews/review?slug=a-zimmermann-symphonies-ehrhardt |website=Gramophone}}</ref> The date is uncertain but it is most probably from the peak of the composer's activity in the 1770s. The earliest confident date for introducing the trombone to the symphony is therefore Zimmermann's death in 1781.

==== Transition to Romantic period ====
Symphony in E{{Music|flat}} (1807) by Swedish composer [[Joachim Nicolas Eggert]]<ref>{{cite web |last1=Kallai |first1=Avishai |title=Biography of Joachim Nikolas Eggert |url=http://musicalics.com/fr/compositeur/Joachim-Nikolas-Eggert |website=Musicalics |archive-url=https://web.archive.org/web/20141108151031/http://musicalics.com/fr/compositeur/Joachim-Nikolas-Eggert |archive-date=8 November 2014 |url-status=dead }}</ref> features an independent trombone part. [[Ludwig van Beethoven]] is sometimes mistakenly credited with the trombone's introduction into the orchestra, having used it shortly afterwards in his [[Symphony No. 5 (Beethoven)|Symphony No. 5 in C minor]] (1808), [[Symphony No. 6 (Beethoven)|Symphony No. 6 in F major ("Pastoral")]], and [[Symphony No. 9 (Beethoven)|Symphony No. 9 ("Choral")]].