How did Alan Lomax classify European folk singing styles?

The American ethnomusicologist Alan Lomax classified European folk singing into three primary styles based on his research into folk music:

• Eurasian style: Found primarily in southern Europe, parts of Britain, and Ireland, as well as in the Middle East and South Asia. This style is characterized by tense, ornamented vocal delivery and is typically associated with solo singing.1
• Old European style: Characteristic of central, eastern, and parts of northern Europe. This style is more relaxed, utilizing a full voice and is often associated with group singing where voices blend together.1
• Modern European style: Primarily of urban and western European origin, this style functions as a compromise between the Eurasian and old European styles.1

Lomax’s work in this area was part of his broader development of cantometrics, a method involving the statistical analysis of singing styles correlated with anthropological data.2