Joseph Fiala (c1748 - 1816) was a famous Czech composer and performer of his day. Mozart spoke highly of him, and he held a succession of important musical posts at European courts.
Written for the 'Klappentrompete' (keyed trumpet), Divertimento In D dates from the same period as Haydn's Concerto in E flat for the same instrument, and represents a welcome (and technically less demanding) addition to the classical trumpet repertory.
**Trinity College London selected piece (Trumpet, Cornet, Flugel Horn 2010): Divertimento in D, 2nd movt: Allegro (Fiala)