Fog, for solo trombone and piano accompaniment

It's the year-end assignment for my year 3 composition class. While the piano can still theoretically be performed, the trombone is not at all feasible, I remember consulting Alfred Blatter's book on orchestration while the positions are possible but only at much slower speeds and when play rapidly it would be lacking in pitch control; This would be much more suitable for keyed instruments like (contra)Bass clarinet or Bassoon. Still very exotic but definitely tangible.

Note: somehow I no longer have a complete Sibelius copy and while I do have pdfs it would take some time to reconstruct it and make it into youtube...