This is a text description of maprel.gif. It illustrates measures, distances, and their mapping relationship, as described in text preceding and following the illustration. The following calculation uses the formula and values in the illustration to determine the measure of the point at measure 60: (50/100) * (100-20) + 20 = 1/2 * 80 + 20 = 40 + 20 = 60. End of description.