Sackbut

A sackbut is an early form of the trombone used during the Renaissance and Baroque eras. A sackbut has the characteristic telescopic slide of a trombone, used to vary the length of the tube to change pitch, but is distinct from later trombones by its smaller, more cylindrically-proportioned bore, and its less-flared bell. Unlike the earlier slide trumpet from which it evolved, the sackbut possesses a U-shaped slide with two parallel sliding tubes, rather than just one. Records of the term trombone predate the term sackbut by two decades, and evidence for the German term Posaune is even older.