Three levels
Artefact-based instrument building, historically informed performance experiments, and freely inspired composition are different activities. All may be valuable, but they should be named clearly.
From fragment to instrument
A bridge, peg, or wooden fragment permits several plausible completions. Makers choose dimensions, wood, strings, and tension; every choice changes sound and playability.
The melody remains lost
Instruments reveal possible ranges, not the melodies once played. Later Scandinavian folk traditions can inspire comparison but are not unchanged recordings of the tenth century.
Voice, language, and space
Old Norse pronunciation, metre, and resonant spaces can be studied. Here too, research produces ranges rather than one correct solution. Studio production and stage amplification are plainly modern.
Useful labels
“Instrument reconstructed from a find” is more precise than “authentic Viking music”. Hrafnspeki asks of every recording: what derives from evidence, what from comparison, and what from art?