Kraviklyra Tuned A C D E F G a if the strings are numbered 7 6 5 4 3 2 1 then the main them to start with is 5 6 5 3 4 5 6 Chords that can be played to accompany the voice include 5 and 3 and 2 and 4 for example.
You can see and hear Einars excellent rendition on the Vikings Tv show as well as on Youtube videos like this one: 
Instruments to order and plans to make your own available from my various shops online:
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