Beavon-Ham - bitonal contours

 All bitonal contours involving a mid tone:

    U+1DC4  (mid-high contour tone, e.g.,  [a᷄])
    U+1DC5  (low-mid contour tone, e.g.,  [a᷅])
    U+1DC6  (mid-low contour tone, e.g.,  [a᷆])
    U+1DC7  (high-mid contour tone, e.g.,  [a᷇])
