Well, that song or melody is not more viking than knights are viking. Year 1300 lots of things had changed and music was heavily influenced by the current trends in medieval music. The viking age was long past and if you would ask about vikings people would just look strangely at you and shake their heads.
Then they may just kill you because you were a stranger and you better be sure. Talking about pirates and being from far away. Anyway, there was no real penalty for killing someone far of like an englishman in at least Sweden back then.