     for n in [@lowest..@highest]
       @draw(n)
 
-  makecallback: ->
+  makecallback: (cb2) ->
     pressed = []
     convertfreq = (f) ->
       round(69 + ln(f / 440) * 12 / ln(2))


###

class Keyboard
  constructor: (options = {}) ->
    defwidth = if options.kh? then (options.kh / 5) else 10
    @kw = options.kw ? defwidth
    @kh = options.kh ? @kw * 5
    @bkw = options.bkw ? @kw * 3 / 5
    @bkh = options.bkh ? @kh * 3 / 5
    @lowest = options.lowest ? 21
    @highest = options.highest ? 108
    @x = options.x ? 0
    @y = options.y ? 0
    @center = floor((@lowest + @highest) / 2)
    @kt = new Turtle
    @kt.ht()
    @kt.speed Infinity
    @pt = new Turtle
    @pt.ht()
    do @drawall

  # white-key position: gives a number
  # that increases by 1 for every white

        startx += 2 * fkw + @bkw - @kw
      when 12
        startx += 3 * fkw + 2 * @bkw - 2 * @kw
    kt.jump startx, starty
    switch ks
      when 1
        kt.fd @kh
