Grottasöngr
Grottasöngr or the Song of Grótti is an Old Norse poem, sometimes counted among the poems of the Poetic Edda as it appears in manuscripts that are later than the Codex Regius. The tradition is also preserved in one of the manuscripts of Snorri Sturluson's Prose Edda along with some explanation of its context.
The myth has also survived independently as modified Scandinavian fairy tales, one of them called Why the Sea Is Salt, collected by Peter Christen Asbjørnsen and Jørgen Moe in their Norske Folkeeventyr. Moreover, Gróttasöngr had great social and political impact in Sweden during the 20th century as it was modernized in the form of Den nya Grottesången by Viktor Rydberg.
Poetic Edda
Though not originally included in the Codex Regius, Gróttasöngr is included in many later editions of the Poetic Edda.Gróttasöngr is the work song of two young slave girls bought in Sweden by the Danish King Frodi. The girls are brought to a magic grind stone to grind out wealth for the king and sing for his household.