fftSize = 64

b = EDrums('x*o*x*o-')
b.amp = .75

fft = FFT( fftSize )

a = Canvas()

a.draw = function() {
  a.clear()
  var numBars = fftSize / 2,
      barWidth = ( a.width - 1 ) / numBars,
      barColor = null, 
      value = null

  for( var i = 0; i < numBars; i++ ) {
    barColor = Color({ h:( i / numBars ) * 255, s:255, v:255 })

    // read FFT value, which ranges from 0-255, and scale it.
    value = ( fft[ i ] / 255 ) * a.height*0.5

    a.rectangle( i*barWidth, a.height-value, barWidth, value )
    a.fill( barColor.rgbString() ) 

  }
}