The Icelandic Saga of Herrauðr & Bósi, composed sometime before 1350, mentions several tunes played on an instrument called harp:
Herrauðr, son of King Hringr in Eystra-Gautland, went with his friend Bósi to a temple in Bjarmaland to fetch the egg of an enormous bird, and rescued Princess Hleiðr, who was held prisoner there. Of course, Herrauðr fell in love with her. Unfortunately, Hleiðr was then promised by her brother, king Godmundr in Glæsisvellir, as a wife to Siggeir, son of king Harek of Bjarmaland. So, the two heroes slain the king’s harper Sigurðr, take his harp, dress as musicians and go to Hleiðr’s wedding, to kidnap her… The harp was big, so big that a man could stand upright inside.
During the ceremony, Bósi played five tunes on the harp, which carry names: Gýgjarslag, Drömbuð, Hjarrandahljóð, Faldafeykir, and Rammaslag. When he played Faldafeykir (= “Coif-Blower”), the women’s coifs were blown off their heads, and when he played Rammaslag (“the powerful”), the entire court was set into extatic dancing. – In this context, it might be interesting that Morten Levy (1974) suggested a connection between Rammaslag and some dance tunes in the traditional music of Setesdal, Norway, which are called rammeslåt or rammeslag, and are believed to have extatic magical power…
Finally, they took the bride, locked her inside the harp, carried the harp down to their ship and went on board…
The entire saga at Heimskringla.no (in Norse and in Norwegian)
Morten Levy (1974): Den stærke slått. Om magisk musik fra sagatiden og dens genklang hos norske spillemænd. Höjbjerg: Wormianum, 154 pp.