All 3 movements have three C flute parts, an alto flute part which needs 2 players and 2 different bass parts, which could go on a contra as a 3rd part in groups that had plenty of bass. I’ll play the B2/C part in the regular bass range on the synth for best balance in our group unless we get another acoustic bass. There is no piccolo part in any movement. All parts have melody sections, accompaniment or counter melody, and rhythm/tempo maintenance. The original horn solo is in several parts in all three movements. Rhythmically it is not hard, but intonation, clean phrasing, and speed should challenge.
Years ago my med school lab partner and I did one of these on horn and piano in a chamber concert- exuberant pieces and crowd pleasers done well. The fast tempos of first and 3rd movements, and slow 2nd are taken from a performance in the late 50’s of one of the purported best ever done. (Second movement was set very slow, but seemed more appropriate to an extremely sonorous solo horn than our ensemble at that tempo- around 60.)