Grand Trio Concertant, Opus 31 composed by Johann Wilhelm Gabrielsky (1791-1846)
Edited by Albert J. Andraud for 3 Flutes
Includes score and parts
A German flutist of the early 19th century, this trio does have the melodic line being shared between the parts.
Allegro con giusto
Theme with four variations
(The fourth variation does have a cadenza in the first part, which leads into the Rondo section.)