A Japanese vocal coach made an analysis about Ayu voice from a professional view.
Too bad my Japanese is not good enough to understand but it’s seems like a positive analysis and I believe he think that she is underestimated technically. From what I get he compare her past and present voices. I believe he don't really know well her discography because he think the only falsetto notes she is able to do are in Seasons.
If someone is able to summarize what he said I would be glad
