On the one hand, the catalogue of 257 works from the CeBeDem library, as presented to us in 2009, is available for inspection here.
On the other hand a chronological-systematic list, by Dr. J.L.Broeckx, which reaches until the edition date of the book '1945 Van-Nu-en-strakser-der-Muziek'.
And at last a list of various recordings made by the BRT. [actual VRT - Belgische Radio & Televisie]
Lied van Mignon
The poem "Mignon, Kennst du das Land" from Goethe has been used by several composers and written into a Lied.
Lodewijk Mortelmans had promised his master Peter Benoit only to compose lieder from lyrics of flemisch poets.
Although, he made 2 exceptions on this rule: first for "Lied of Mignon", and second for "L'ennemi" written by Baudelaire.
Opera: De Kinderen der Zee
The 'Children of the Sea' is Mortelmans' sole opera. It was probably intended to add luster to the silver jubilee of the Antwerp Royal Flemish Opera in 1918, but World War I precluded that. It was eventually decided to proclaim the 1919-1920 season the jubilee season, and to put two popular Flemish operas on again, Jan Block's'Herbergprinses' (The Inn's Princess) and 'Quinten Massys' by Emile Wambach.
De 'Kinderen der Zee' was premiered on March 27, 1920.
Its libretto was written by Rafaël Verhulst (1866-1941), a dramatist,; its subtitle, appropriately, is'dramatisch zangspel in drie bedrijven' (literally 'tragic song-play in three acts').
It is rhymed and has arias, duets, ensembles and choirs. Its publication in 1900, which had been awarded the prize in the 'competition for drama writing' by the city of Antwerp, already mentioned that it 'was being set to music by Lodewijk Mortelmans'.
The action is near the sea, in the 17th century, 'when lighthouses were still lit with real fires'.
From CD Phaedra IFF 92097 by Jan Dewilde, SVM
Fragment of the "theme of the fateful forecast" from "De Kinderen der Zee"
to my friend Jules Baetes
Lod. Mortelmans 30 jan. 1904
Extract from '1945 Van-Nu-en-strakser-der-Muziek:
When Mortelmans won the 'Prix de Rome' in 1893, the thought of an opera was already in his mind.
He stated that he had been asked to create a work for the Nederlandsch Lyrisch Tooneel, but a suitable libretto was late. The difficulties with regard to the text were all the heavier, since Mortelmans declared that he would not write a traditional opera under any circumstances. He sees himself for the choice between the Wagnerian music drama, and the lyrical drama as Benoit and Fibich conceive it.