Nykken is a symphonic poem

Symphonic poem

A symphonic poem or tone poem is a piece of orchestral music in a single continuous section in which the content of a poem, a story or novel, a painting, a landscape or another source is illustrated or evoked. The term was first applied by Hungarian composer Franz Liszt to his 13 works in this vein...

 composed by the Norwegian

Norway

Norway , officially the Kingdom of Norway, is a Nordic unitary constitutional monarchy whose territory comprises the western portion of the Scandinavian Peninsula, Jan Mayen, and the Arctic archipelago of Svalbard and Bouvet Island. Norway has a total area of and a population of about 4.9 million...

 composer Geirr Tveitt

Geirr Tveitt

Geirr Tveitt, born Nils Tveit was a Norwegian composer and pianist. Tveitt was a central figure of the national movement in Norwegian cultural life during the 1930s.-Early years:...

 in 1957.

It is written for orchestra

Orchestra

An orchestra is a sizable instrumental ensemble that contains sections of string, brass, woodwind, and percussion instruments. The term orchestra derives from the Greek ορχήστρα, the name for the area in front of an ancient Greek stage reserved for the Greek chorus...

 and several solo instruments, although they do not have any solo roles. It was written on demand for the Norwegian Broadcasting Corporation (NRK) and survived a fire in 1970 by being kept safe in their archives. It is built on a Norwegian legend about the sea-creature nøkken

Nix

The Neck/Nixie are shapeshifting water spirits who usually appear in human form. The spirit has appeared in the myths and legends of all Germanic peoples in Europe....

, and is based on a story about him transforming into a beautiful, white horse and getting out of a silent pond. The horse lures a young boy onto its back and takes him with it back into the pond, generating a great disturbance in the normally so silent water. A normal performance lasts about 16-18 minutes.

Nykken (Norwegian

Norwegian language

Norwegian is a North Germanic language spoken primarily in Norway, where it is the official language. Together with Swedish and Danish, Norwegian forms a continuum of more or less mutually intelligible local and regional variants .These Scandinavian languages together with the Faroese language...

) or Näcken (Swedish

Swedish language

Swedish is a North Germanic language, spoken by approximately 10 million people, predominantly in Sweden and parts of Finland, especially along its coast and on the Åland islands. It is largely mutually intelligible with Norwegian and Danish...

), originating from Old Norse

Old Norse

Old Norse is a North Germanic language that was spoken by inhabitants of Scandinavia and inhabitants of their overseas settlements during the Viking Age, until about 1300....

, is a spirit said to exist along the borders of water and land. People would often say prayers to the Nykken before swimming so that no harm would come to them.