Joseph Leopold Eybler (8 February 1765 – 24 July 1846) was an Austrian composer and contemporary of Wolfgang Amadeus Mozart.

Eybler was born into a musical family in Schwechat near Vienna.^[1] His father was a teacher, choir director and friend of the Haydn family. Joseph Eybler studied music with his father before attending Stephansdom (the cathedral school of St. Stephen's Boys College) in Vienna. He studied composition under Johann Georg Albrechtsberger, who declared him to be the greatest musical genius in Vienna apart from Mozart. He also received praise from Haydn who was his friend, distant cousin and patron.

In 1792 he became choir director at the Karmeliterkirche (Carmelite Church) in Vienna. Two years later he moved to the Schottenkloster, where he remained for the next thirty years (1794–1824). Eybler also held court posts, including that of court Kapellmeister (chapel master) (1824–33). The Empress Marie Therese commissioned many works from him, including the Requiem in C minor (1803).

Through Joseph Haydn, Eybler met Mozart, who gave him some lessons and entrusted him with the rehearsal of his opera Così fan tutte. Eybler also conducted some performances of Così fan tutte.

On May 30, 1790, Mozart wrote a testimonial for the young Eybler: "I, the undersigned, attest herewith that I have found the bearer of this, Herr Joseph Eybler, to be a worthy pupil of his famous master Albrechtsberger, a well-grounded composer, equally skilled at chamber music and the church style, fully experienced in the art of the song, also an accomplished organ and clavier player; in short a young musician such, one can only regret, as so seldom has his equal."^[2]

Mozart and Eybler remained friends to the end. As Eybler wrote: "I had the good fortune to keep his friendship without reservation until he died, and carried him, put him to bed and helped to nurse him during his last painful illness."^[3]

After Mozart's death, Constanze Mozart asked Eybler to complete her husband's Requiem. Eybler tried but could not complete the commission perhaps, it is thought, because of his great respect for the music of his friend Mozart. (Franz Xaver Süßmayr completed the task).

In 1833 Eybler had a stroke while conducting Mozart's Requiem and thereafter could not fulfill his duties at the Court. For his service to the Court, Eybler was raised to the nobility in 1835 and was known henceforth as Joseph Leopold, Edler von Eybler. He died in Vienna on 24 July 1846.^[1]

Eybler's main compositions were sacred music, including oratorios, masses, cantatas, offertories, graduals, and his requiem. His other works include an opera, instrumental music (especially his string quintets), and songs.

Of special note may be the Clarinet Concerto (HV160) he wrote most probably for "Mozart's" clarinetist Anton Stadler. A recording of this concerto by Dieter Klöcker is available on the Novalis music label.^[4]

• Eva Badura-Skoda with Hildegard Herrmann-Schneider (n.d.) "Eybler, Joseph [Josef] Leopold, Edler von". Grove Music Online (subscription required)
• Entry for Eybler in The Grove Concise Dictionary of Music, 1994, Oxford University Press, Inc.
• Program notes by Cordula Timm-Hartmann for Eybler's String Quintet and String Trio, 2005 recording by the Quintett Momento Musicale (MDG 603 1321-2)
• Joseph Eybler String Quintet Op. 6 No. 1, sound-bites and short bio
• Article on Eybler in Mozart Forum by Gary Smith

Wikimedia Commons has media related to Joseph von Eybler.

• Free scores by Joseph Leopold Eybler at the International Music Score Library Project (IMSLP)
• Free scores by Joseph Leopold Eybler in the Choral Public Domain Library (ChoralWiki)