Ausbund has lyrics. No melodies. 140 hymns passed orally. From Vorsinger to Vorsinger. Father to son. Community to community.
Mutations
Over 460 years, melodies changed. Each community sings slightly differently. Lancaster Lob Lied and Ohio Lob Lied — same text, different melodies. Both 'correct.' Both 'original.' Because there is no original.
Musicologists
In the 1960s, scholars began recording Amish melodies. Discovered: some are medieval chants from the 12th-13th century, reaching the 21st century alive. Nowhere else in the world have they survived.