A (mostly) great introduction to this family of instruments by a knowledgeable and masterful musician. My only minor nitpicks, which I can't seem to help picking, are when he says "the diatonic accordion was never assimilated into any American folk tradition". He then goes on to discuss at length the role of the accordion in Cajun music, which he distinguishes from "American" music. Louisiana joined the United States in 1803, long before the introduction of the diatonic accordion in the 1880's. How is Cajun less American than bluegrass? He then presents the piano accordion as the next step in the evolution from diatonic instruments, omitting the prior existence of the chromatic button accordion, which he briefly mentions toward the end of the video, implying that it was a later invention. Also, on a technical note, his claim that the little metal bells protruding from the helikon accordion are what gives it its powerful bass is incorrect, as these are purely decorative, and it's only the size of the reeds that gives it that sound. Other than that, it's great, and his informed playing of many different styles and instruments is impressive.