Wikipedia
Elverskud
Elverskud is a ballad for soloist, choir and orchestra by Niels W. Gade from 1854.
Gade's oeuvre contains many concert pieces of various lengths for orchestra, choir and soloists. Depending on which one counts, there are up to 16 of them, mostly referred to as "cantata". The longest of the pieces can take up to an hour. Some of the pieces are almost semi-operas or concert operas with dramatic development.