Although the trombone first appeared in its earliest sackbut form in the 15th century, the exact origin of the smaller alto sized instrument is unclear.
Due to the advanced technique (particularly lip trills) required in this concerto, it was considered too difficult for the trombone and musicologists concluded that it was most likely written for the French horn.
In addition to Leopold Mozart and Wagenseil, Michael Haydn's Serenade in D (1764) with its extended range, trills, technique, and endurance demands contributes to this idea that there was perhaps a golden age of the alto trombone between 1756 and 1780 and was this piece was also most likely written for Thomas Gschladt.
[8] While some first trombonists continued to use the alto trombone as indicated, it was unfashionable in orchestras until the late 20th century, when it began to enjoy something of a revival.
[8] Contemporary composers have written solo works for the alto trombone, including Eric Ewazen, Christian Lindberg, Torsten Nilsson [nl; sv], and Jan Sandström.
Many manufacturers offer an alto model in their trombone range, including Yamaha, Bach, Conn, SE Shires, Thein, Rath, and others.
The timbre of the alto is brighter than that of the tenor or bass trombone, and constitutes its principal strength and point of difference.
The alto trombone has primarily been used in choral, orchestral and operatic settings, and came to some prominence in the early 19th century, particularly in the symphonies of Schubert, Schumann, Brahms and Mendelssohn.