Johann Georg Albrechtsberger (1731-1809) was an Austrian composer, organist, and music theorist and one of the teachers of Ludwig van Beethoven.
Albrechtsberger was born at Klosterneuburg, near Vienna. He originally studied music at Melk Abbey and philosophy at a Benedictine seminary in Vienna and became one of the most learned and skillful contrapuntists of his age.
Albrechtsberger's earliest classmates included Michael Haydn and Franz Joseph Aumann. After being employed as organist at Raab in 1755 and Maria Taferl in 1757, he was appointed Thurnermeister back at Melk Abbey.
In 1772 he was appointed organist to the court of Vienna, and in 1792 Kapellmeister of St. Stephen's Cathedral.
His fame as a theorist attracted to him in the Austrian capital a large number of pupils, some of whom afterwards became eminent musicians.
Among these were Johann Nepomuk Hummel, Ignaz Moscheles, Josef Weigl (1766–1846), Ludwig-Wilhelm Tepper de Ferguson (1768 – after 1824), Antonio Casimir Cartellieri, Ludwig van Beethoven, Anton Reicha and Franz Xaver Wolfgang Mozart.
His published compositions consist of preludes, fugues and sonatas for the piano and organ, string quartets, etc.; but the greater proportion of his works, vocal and instrumental, exists only in manuscript. They are in the library of the Vienna Gesellschaft der Musikfreunde.