Quote from this site:

"Otto Malling (1848-1915)

Otto Malling was held in high esteem in Danish musical life at the turn of the century, and as a cathedral organist in Copenhagen and principal of the Royal Academy
became the official heir to the Odin-like figure J.P.E. Hartmann. Otto Malling mainly composed organ works and vocal
music, but he also wrote one of the most appealing Danish piano trios and one of the few Danish piano concertos of the
Romantic period. His grasp of music was impressively sure, and he could operate with Late Romantic effects with an
inevitability that few Danish composers possessed. His technical skill in composing was so great that he wrote the first
Danish textbook in orchestration (still the only one of its kind). The organ works brought Malling success abroad, but
paradoxically helped to ensure that after his death he was quickly forgotten in his native country. Malling’s arch-Romantic
programme music, in a harmonic idiom dominated by French Romanticism, was bound to be anathema to his contemporary, the
church music reformer Thomas Laub. Today, a less dogmatic age can see Otto Malling’s works as a high point in
Danish Romantic sacred music."

Added info: He has also written a beautiful string octet, op 50.
The string octet is now published: Dohr Verlag, Köln (Germany) edited
by Wolfgang Birtel. Score: ISMN M-2020-0758-7, Parts ISMN-2020-0759-4.