You saw it here first! A triple flat F double sharp used to get from F major (tuned high) to D major (tuned lows) in a gross chromatic fugue, finale of String Quintet (HGI 0589, 2015). No guarantees that it will survive the edit/review … I don’t really want a hostile ‘cellist. ex3

Update: had to revise the triple flat double sharp away. Summery, octave adjusted, here. ex4