I know nothing but these sites.
Yamanashi Pref. Minyo
http://www1.ocn.ne.jp/~chibu/minyou/minyou.html
Siga Pref. Minyo
http://www1.ocn.ne.jp/~chibu/minyou/minyou.html
Akita Pref. Minyo
http://minnyou.hoops.livedoor.com/pub2/pub2/muvi.htm
Okinawa Pref. Minyo
http://www.sansinya.com/minyo-2.htm
http://www.cosmos.ne.jp/RV-OKINAWA/mp3/MP3_1.html
