Gade and J.P.E. Hartmann formed the axis of Danish music through over half a century of Romanticism. Of the two, it was Gade who was to have the most enduring importance for posterity, and Gade, more down-to-earth than the haut-bourgeois Hartmann, who had the best grasp of the living musical milieu.
Two people were of crucial importance to Niels W. Gade's music. The first was A.P. Berggreen. Gade became a pupil of Berggreen at a time when his teacher was determined to give folk melodies an influence on art music. In that respect Gade was a pioneer, and with his First Symphony and his overture Efterklange af Ossian (Echoes of Ossian) wrote the hitherto purest National-Romantic music in Denmark.
The second key figure in Niels W. Gade's life was Mendelssohn. Mendelssohn performed Gade's First Symphony with great enthusiasm, and this was the beginning of a close association between the two. Mendelssohn convinced Gade of the limitations of National Romanticism, and on his return to Denmark, Gade introduced Mendelssohn's elegant, classicizing Romanticism, and remained himself with the style for the rest of his life.
Only on a few occasions was Niels W. Gade again to write in the "Nordic tone". One example was the choral work Elverskud (The Elf King's Daughter), one of the most popular Danish musical works of all. At all events Gade's perfectionism - and status - meant that each new work was considered unassailable.
NIels W. Gade composed eight symphonies, several major choral works with orchestra, much chamber music, songs and piano pieces. He influenced all Danish composers, all the way up to Carl Nielsen and Rued Langgaard.