Copy a Sound into a Target

# copies the "source"  sound into the "target" sound starting at "start" in "target"
def copy (source, target, start):
  targetIndex = start
  for sourceIndex in range(0, getLength(source)):
    sourceValue = getSampleValueAt (source, sourceIndex)
    setSampleValueAt (target, targetIndex, sourceValue)
    targetIndex = targetIndex + 1