I've mentioned the Dokumentasjons-prosjektet in a number of past discussions here; see, for instance, a 'Two Sisters' thread eight years back:  Binnorie - Icelandic version.

A useful page to start from there is  Ballader I Norge - Ballads in Norway. As Howard says, only some pages are available in English and parts of the site haven't worked for years (the 'ballad jukebox' was broken for a long time and has now disappeared altogether) but there seems to be some sign that piecemeal work is being done and that updates may eventually appear, perhaps with music notation where it survives. We will have to see.

Meanwhile, some of Svend Grundtvig's 19th century Danish collections of song texts, folktales and so on can now be seen at the Internet Archive:

Svend Grundtvig at the Internet Archive