Apparently, a grape variety I never heard of, Gouais Blanc, is the mother grape of such disorderly favorites as Gamay, Melon, Romorantin, Aligote, and another obscure grape variety that apparently can be made into a decent sparkler.
Link
N.B.: Corrected from a previous version that botched the use of "varietal." Hat tip to Thor and Jeff.
Link
N.B.: Corrected from a previous version that botched the use of "varietal." Hat tip to Thor and Jeff.