The purpose of this task is to establish participants' abilities to identify rhythmical units and subunits within a given phrase. The test rhythm consists of a number of indentifiable rhythmical units, each of which is subdivided into a number of subunits. The specimen group is designed to include one of each of the following alterations to the test rhythm:

• Total number of units is different
• Total number of units is the same, but the duration of one unit is different
• Total number of units is the same, but the number of subunits in one unit is different
• Total number of units is the same, but the duration of the subunits within one unit is different